Conductivity
Superconductivity theory
When crystal lattices of solids are formed from atoms of various substances, valence electrons located in the outer orbits of the atoms interact with each other in different ways and, as a result, behave differently (see band
solid state superconductivity theory and theory
molecular orbitals). Thus, the freedom of valence electrons to move within a substance is determined by its molecular-crystalline structure. In general, according to their electrically conductive properties, all substances can (with some degree of convention) be divided into three categories, each of which has pronounced characteristics of the behavior of valence electrons under the influence of an external electric field.
Conductors
In some substances, valence electrons move freely between atoms. First of all, this category includes metals in which the electrons of the outer shells are literally “common property” of the atoms of the crystal lattice (see.
chemical bonds and electronic theory of conductivity).
If you apply an electrical voltage to such a substance (for example, connect the poles of a battery to its two ends), the electrons will begin to move unhindered in an orderly manner towards the south pole of the potential difference, thereby creating an electric current. Conducting substances of this kind are usually called conductors. The most common conductors in technology are, of course, metals, primarily copper and aluminum, which have minimal electrical resistance and are quite widespread in earthly nature. It is from them that high-voltage electrical cables and household electrical wiring are mainly made. There are other types of materials that have good electrical conductivity, such as salt, alkaline and acidic solutions, as well as plasma and some types of long organic molecules.
In this regard, it is important to remember that electrical conductivity can be caused by the presence in a substance not only of free electrons, but also of free positively and negatively charged ions of chemical compounds. In particular, even in ordinary tap water there are so many different salts dissolved, which decompose when dissolved into negatively charged cations and positively charged anions, that water (even fresh water) is a very good conductor, and this should not be forgotten when working with electrical equipment in conditions of high humidity - otherwise you can get a very noticeable electric shock.
Insulators
In many other substances (particularly glass, porcelain, plastics), electrons are tightly bound to atoms or molecules and
are not capable of free movement under the influence of externally applied electrical voltage. Such materials are called insulators.
Most often in modern technology, various plastics are used as electrical insulators. In fact, any plastic consists of polymer molecules - that is, very long chains of organic (hydrogen-carbon) compounds - which also form complex and very strong interweavings. The easiest way to imagine the structure of the polymer is in the form of a plate of long and thin noodles entangled and stuck together. In such materials, electrons are tightly bound to their ultra-long molecules and are not able to leave them under the influence of external voltage. Amorphous substances such as glass, porcelain or rubber, which do not have a rigid crystalline structure, also have good insulating properties. They are also often used as electrical insulators.
Both conductors and insulators play an important role in our technological civilization, which uses electricity as the main means of transmitting energy over distances. Electricity is carried through conductors from power plants to our homes and to various industrial enterprises, and insulators ensure our safety by protecting us from the harmful consequences of direct contact of the human body with high electrical voltage.
Semiconductors
Finally, there is a small category of chemical elements that occupy an intermediate position between metals and insulators (the most famous of them are silicon and germanium). In the crystal lattices of these substances, all valence electrons, at first glance, are connected by chemical bonds and it would seem that there should be no free electrons left to ensure electrical conductivity. However, in reality the situation looks somewhat different, since some electrons are knocked out of their outer orbits as a result of thermal motion due to insufficient energy of their binding with atoms. As a result, at temperatures above absolute zero they still have a certain electrical conductivity under the influence of external voltage. Their conductivity coefficient is quite low (silicon conducts electric current millions of times worse than copper), but they still conduct some current, albeit insignificant. Such substances are called semiconductors.
As it turned out as a result of research, electrical conductivity in semiconductors, however, is due not only to the movement of free electrons (the so-called n-conductivity due to the directional movement of negatively charged particles). There is also a second mechanism of electrical conductivity - and a very unusual one. When an electron is released from the crystal lattice of a semiconductor due to thermal motion, a so-called hole is formed in its place - a positively charged cell of the crystal structure, which can at any moment be occupied by a negatively charged electron that has jumped into it from the outer orbit of a neighboring atom, where, in turn, , a new positively charged hole is formed. Such a process can continue for as long as desired, and from the outside (on a macroscopic scale) everything will look like the electric current under external voltage is caused not by the movement of electrons (which just jump from the outer orbit of one atom to the outer orbit of a neighboring atom), but by a directed migration of a positively charged hole (electron deficiency) towards the negative pole of the applied potential difference. As a result, a second type of conductivity is observed in semiconductors (the so-called hole or p-conductivity), which is, of course, also caused by the movement of negatively charged electrons, but from the point of view of the macroscopic properties of the substance, it appears to be a directed current of positively charged holes towards the negative pole.
The phenomenon of hole conduction is most easily illustrated using the example of a traffic jam. As the car stuck in it moves forward, a free space is formed in its place, which is immediately occupied by the next car, whose place is immediately occupied by a third car, etc. This process can be imagined in two ways: you can describe the rare movement of individual cars from among those standing in a long traffic jam; It is easier, however, to characterize the situation from the point of view of the episodic movement in the opposite direction of the few voids between the cars stuck in the traffic jam. It is guided by this analogy that physicists talk about hole conductivity, conventionally taking it for granted that electric current is conducted not due to the movement of numerous, but rarely moving negatively charged electrons, but due to the movement in the opposite direction of positively charged voids in the outer orbits of semiconductor atoms, which they agreed to call holes. Thus, the dualism of electron-hole conductivity is purely conditional, since from a physical point of view, the current in semiconductors is in any case determined exclusively by the directional movement of electrons.
Semiconductors have found wide practical application in modern radio electronics and computer technology precisely due to the fact that their conductive properties are easily and accurately controlled by changing external conditions.
electronic conductivity theory
The electrical conductivity of solids is due to the collective directed movement of free electrons
Catalog of tasks.
Tasks 3. Periodic table
Answer:
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
It is known that with an increase in the atomic number of an element in periods, the metallic properties of atoms decrease, and in groups they increase. Arrange the following elements in order of increasing metallic properties: Write down the designations of the elements in the required sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
It is known that with an increase in the atomic number of an element in periods, the metallic properties of atoms decrease, and in groups they increase. Arrange in order of increasing metallic properties the following elements:
Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
It is known that with an increase in the atomic number of an element in periods, the metallic properties of atoms decrease, and in groups they increase. Arrange in order of increasing metallic properties the following elements:
Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
It is known that with an increase in the atomic number of an element in periods, the metallic properties of atoms decrease, and in groups they increase. Arrange in order of increasing metallic properties the following elements:
Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
It is known that with an increase in the atomic number of an element in periods, the metallic properties of atoms decrease, and in groups they increase. Arrange in order of increasing metallic properties the following elements:
Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
It is known that with an increase in the atomic number of an element in periods, the metallic properties of atoms decrease, and in groups they increase. Arrange the following elements in order of increasing metallic properties: Write down the designations of the elements in the required sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
It is known that with an increase in the atomic number of an element in periods, the metallic properties of atoms decrease, and in groups they increase. Arrange in order of increasing metallic properties the following elements:
Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
It is known that with an increase in the atomic number of an element in periods, the metallic properties of atoms decrease, and in groups they increase. Arrange in order of increasing metallic properties the following elements:
Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radius: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of increasing atomic radius: Write down the signs of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of decreasing atomic radius: Write down the designations of the elements in the desired sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the electronegativity of atoms increases, and in groups it decreases.
Considering these patterns, arrange the following elements in order of increasing electronegativity: Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the electronegativity of atoms increases, and in groups it decreases.
Considering these patterns, arrange the following elements in order of decreasing electronegativity: Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
Considering these patterns, arrange the following elements in order of increasing the acidic properties of higher oxides: Write down the designations of the elements in the required sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that the acidic character of higher oxides of elements increases in periods with increasing nuclear charge, and decreases in groups.
Considering these patterns, arrange the following elements in order of weakening the acidic properties of higher oxides: Write down the designations of the elements in the required sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that acid
The character of oxygen-free acids increases with increasing charge of the atomic nucleus both in periods and in groups.
Considering these patterns, arrange hydrogen compounds in order of increasing acidic properties:
In your answer, indicate the numbers of chemical formulas in the correct sequence.
Answer:
The periodic system of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, the methods of obtaining substances, as well as their location in nature. For example, it is known that the ease of electron donation by atoms of elements in periods with increasing nuclear charge decreases, and in groups it increases.
Considering these patterns, arrange the following elements in order of increasing ease of electron loss: Write down the designations of the elements in the required sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
Periodic table of chemical elements D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds, the patterns of changes in these properties, methods for obtaining substances, as well as their location in nature. For example, it is known that with an increase in the atomic number of a chemical element in periods, the radii of atoms decrease, and in groups they increase.
Considering these patterns, arrange the following elements in order of decreasing atomic radius: N, Al, C, Si. Write down the designations of the elements in the correct sequence.
In your answer, indicate the designations of the elements, separating them with &. For example, 11&22.
Answer:
Periodic table of chemical elements D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the ordinal number of a chemical element, the basic nature of the oxide decreases in periods and increases in groups.
Considering these patterns, arrange the following elements in order of increasing basicity of the oxides: Na, Al, Mg, B. Write the symbols of the elements in the desired sequence.
Answer:
Periodic table of chemical elements D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the ordinal number of a chemical element, the basic nature of the oxide decreases in periods and increases in groups. Considering these patterns, arrange the following elements in order of increasing basicity of the oxides: Mg, Al, K, Ca. Write the symbols of the elements in the correct sequence.
Answer:
Considering these patterns, arrange the following elements in order of increasing electronegativity: chlorine, silicon, sulfur, phosphorus. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
Considering these patterns, arrange the following elements in order of increasing reducing ability: calcium, sodium, magnesium, potassium. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
Considering these patterns, arrange the following elements in order of decreasing atomic radii: aluminum, carbon, boron, silicon. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
Considering these patterns, arrange the following elements in order of increasing the acidic properties of their higher oxides: silicon, chlorine, phosphorus, sulfur. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the basic properties of oxides weaken in periods, and intensify in groups.
Considering these patterns, arrange the following elements in order of weakening of the main properties of their oxides: aluminum, phosphorus, magnesium, silicon. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
Pe-ri-o-di-che-skaya si-ste-ma hi-mi-che-skih elements-men D. I. Men-de-le-e-va - god-ga-toe store -More information about chemical elements, their properties and the properties of their compounds. So, for example, it is known that with an increase in the number of hi-mi-che-elements men-ta acidic properties of higher hydro-rock-si-ds in pe-ri-o-dah usi-li-va-et-sya, and in groups donkey-be-va- et.
Teach these laws, settle them in order to enhance the acidic properties of their higher hydrides. rock-si-dov the following elements: carbon-le-rod, boron, beryl-lium, nitrogen. In this regard, there are symbols of the elements in the necessary after-the-tele-no-sti.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the ordinal number of a chemical element, the basic character of hydroxides weakens in periods and increases in groups.
Considering these patterns, arrange the following elements in order of strengthening the basic properties of their hydroxides: calcium, beryllium, strontium, magnesium. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the ability of atoms to accept electrons - electronegativity - increases in periods, and weakens in groups.
Considering these patterns, arrange the following elements in order of decreasing electronegativity: nitrogen, oxygen, boron, carbon. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the ability of atoms to give up electrons - the reducing ability - weakens in periods, and increases in groups.
Considering these patterns, arrange the following elements in order of weakening reducing ability: nitrogen, fluorine, carbon, oxygen. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the radii of atoms in periods decrease and in groups increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: oxygen, fluorine, sulfur, chlorine. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the acidic nature of higher oxides increases in periods and weakens in groups.
Considering these patterns, arrange the following elements in order of weakening the acidic properties of their higher oxides: silicon, chlorine, phosphorus, sulfur. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
Considering these patterns, arrange the following elements in order of strengthening the basic properties of their oxides: aluminum, sodium, magnesium, silicon. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the ordinal number of a chemical element, the acidic properties of higher hydroxides (acids) increase in periods and weaken in groups.
Considering these patterns, arrange the following elements in order of weakening the acidic properties of their higher hydroxides: carbon, boron, beryllium, nitrogen. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the ability of atoms to accept electrons - electronegativity - increases in periods, and weakens in groups.
Considering these patterns, arrange the following elements in order of increasing electronegativity: nitrogen, fluorine, carbon, oxygen. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the ability to donate electrons - the reducing ability - weakens in periods, and increases in groups.
Considering these patterns, arrange the following elements in order of increasing reducing ability: rubidium, sodium, lithium, potassium. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the radii of atoms in periods decrease and in groups increase.
Considering these patterns, arrange the following elements in order of decreasing atomic radii: phosphorus, carbon, nitrogen, silicon. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the acidic nature of higher oxides increases in periods and weakens in groups.
Considering these patterns, arrange the following elements in order of increasing the acidic properties of their higher oxides: aluminum, sulfur, silicon, phosphorus. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the basic properties of oxides weaken in periods and increase in groups.
Considering these patterns, arrange the following elements in order of weakening of the main properties of their oxides: magnesium, potassium, sodium, calcium. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the radii of atoms in periods decrease and in groups increase.
Considering these patterns, arrange the following elements in order of increasing atomic radii: carbon, boron, beryllium, nitrogen. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
2019 has been declared the International Year of the Periodic Table of Chemical Elements by D. I. Mendeleev. The world scientific community will celebrate the 150th anniversary of the discovery of the Periodic Law of Chemical Elements by D. I. Mendeleev in 1869. The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the radii of atoms in periods decrease and in groups increase. Considering these patterns, arrange the following elements in order of decreasing atomic radii: aluminum, phosphorus, silicon. In your answer, write down the symbols of the elements in the correct sequence.
Answer:
2019 has been declared the International Year of the Periodic Table of Chemical Elements by D. I. Mendeleev. The world scientific community will celebrate the 150th anniversary of the discovery of the Periodic Law of Chemical Elements by D. I. Mendeleev in 1869. The periodic table of chemical elements by D.I. Mendeleev is a rich repository of information about chemical elements, their properties and the properties of their compounds. For example, it is known that with an increase in the atomic number of a chemical element, the acidic nature of higher oxides increases in periods and weakens in groups. Considering these patterns, arrange the following elements in order of increasing the acidic properties of their higher oxides: chlorine, phosphorus, sulfur. In your answer, write down the symbols of the elements in the correct sequence.
PART 1
1. Metals (M) are located in groups I-III, or in the lower part of groups IV-VI. B groups are made up of metals only.
2. Metal atoms have 1-3 electrons in the outer electron layer and a relatively large atomic radius. Metal atoms tend to lose outer electrons.
3. Simple substances- metals consist of elements connected by a metallic chemical bond, which can be represented by a general diagram:
4. All M are solids, except Hg. The softest metals are group IA, the hardest is Cr.
5. M have thermal and electrical conductivity and have a metallic sheen.
6. Tin has the property of forming two simple substances- white and gray, i.e. the property of allotropy.
7. Complete the table “Properties and applications of some metals.”
PART 2
1. Choose the names of simple substances - metals. Using the letters corresponding to the correct answers, you will form the name of the metal, which means “stone” in Greek: lithium.
2) magnesium L
3) calcium I
5) copper T
7) gold I
8) mercury J
2. The following statements characterizing metals are incorrect:
5) non-plastic and non-malleable
3. Select the four most electrically conductive metals (arrange the numbers in descending order of electrical conductivity) from the list:
1) silver
2) gold
3) aluminum
4) iron
5) manganese
6) potassium
7) sodium
Answer: 1, 2, 3, 7.
4. Make diagrams of the formation of metallic chemical bonds for substances with the formulas:
5. Analyze the drawing “Metal crystal lattice”.
Draw a conclusion about the reasons for the plasticity, thermal and electrical conductivity of metals.
Each metal atom is surrounded by eight neighboring atoms. The detached outer electrons move freely from one formed ion to another, connecting the ionic core of the metal into a giant molecule. The high thermal conductivity and electrical conductivity of metals are due to the presence in their crystal lattices of mobile electrons moving under the influence of an electric field. Most metals are ductile due to the displacement of layers of metal atoms without breaking the bonds between them.
6. Fill out the “Metals” table. Find data for the table using additional sources of information, including the Internet.
7. Using the Internet and other sources of information, prepare a short message on the topic “Mercury in human life” according to the following plan:
1) knowledge about mercury in antiquity and the Middle Ages;
2) toxicity of mercury and safety measures when working with it;
3) the use of mercury in modern industry.
1) Mercury was one of the 7 metals; it is considered the progenitor of all metals; not only mercury itself was used, but also its alloy, cinnabar.
2) It is very toxic, evaporates at room temperature, and poisons humans if inhaled. Accumulating in the body, it affects internal organs, respiratory tracts, hematopoietic organs and the brain.
3) Mercury is used very widely. In the chemical industry as a cathode in the production of sodium hydroxide, as a catalyst in the production of many organic compounds, in the dissolution of uranium blocks (in nuclear energy). This element is used in the manufacture of fluorescent lamps, quartz lamps, pressure gauges, thermometers and other scientific instruments.
