Chemical atomic structure and properties, what determines the chemical properties of an atom

1) From the graph, it is easy to know that each y attracts 4 x at the same time, and then the chemical formula can be determined first, each unit cell contains y 1 (y in the center of the body), containing x: 4 * 1 8 = 1 2 (x at the vertex), so x: y = 1:

2, that is, the chemical formula is xy2, according to x:y = 1:2, since each y attracts 4 x's at the same time, naturally each x attracts 8 y's at the same time.

2) We can know that there is a diagonal relationship between x and x, and if x is placed in the center of a square, then there are 12 points that can be diagonally related to x (drawing). So there are 12 x's in the crystal that are closest to it and have equal distances around each x.

3) 4 x form a tetrahedron, i.e., the methane model, xyx = 109°28'。

4) Each unit cell represents 1 2 XY2, so 1molXY2 contains 2 NA unit cells, so the mass of each unit cell is m 2Na, and the volume is m (2Na*), then the unit cell side length a = cubic root number [m (2na*) and the distance between the two nearest x centers is 2 * a = cubic root number [ 2m (na* )

1) Apparently a Y attracts 4 X's around it, and how many Y's does an X attract? You can do this way, there are two layers of small cubes, and there are 4 small cubes on the upper and lower layers, so that x is just in the center, so one x attracts 8 y's. Therefore, the ratio of the number of atoms of x and y is 1:2

2) In the same way, after two floors are arranged above, there are 12 nearest x adjacent to the center x.

3) 4 X's form a regular tetrahedron, Y is in the center of the tetrahedron, and 2 X's are formed by a Y at an angle of 109°28'

4) Each small cube contains a total volume m of the substance, and there are 2 na y, that is, there are 2 na small cubes, so the volume of a small cube is m (2 na) cubic centimeters, calculate the side length, multiply the root number 2 is the distance of two x.

The chemical properties of an atom are determined by the number of electrons in the outermost shell of the nucleus

The number of outermost electrons is less than (or equal to) 3, such as alkali metal and alkaline earth metal elements, it is easy to lose the outermost electrons and reach a stable structure of the outermost 8 electrons, which makes it have strong metallicity and reducibility. However, this does not apply to subgroup elements, such as gold and silver, which have 1 electron in the outermost shell, and mercury in the outermost shell which has 2 electrons, but they are both inactive.

Atoms are inseparable in chemical reactions, and an atom is composed of a nucleus and electrons moving around the nucleus, and a positive atom contains a dense nucleus and a number of electrons that are negatively charged around the nucleus. Whereas, the nucleus of a negative atom is negatively charged, and the surrounding negative electrons are positively charged.

In an atom, electrons and protons are attracted to each other by the electromagnetic force, which binds the electrons in an electrostatic potential well that surrounds the nucleus, from which external energy is required to escape. The closer the electron is to the nucleus, the greater the force of attraction.

The chemical properties of an atom are mainly manifested in the ability of an atom to gain or lose electrons, and the ability of an atom to gain or lose electrons is determined by the number of nuclear charges and the number of electrons in the outermost shell.

When the number of electron layers is the same, the larger the number of nuclear charges, the smaller the atomic radius, and the easier it is for the atom to get electrons. When the number of electrons in the outermost shell is the same, the larger the number of nuclear charges, the more electron layers, and the larger the atomic radius, the easier it is for the atom to lose electrons. The outermost electrons also follow the stable structure of 8 electrons, and those with less than 4 outermost electrons are easy to lose electrons, and those with more than 4 electrons are easy to gain electrons, which is equal to 4 electrons and easy to form covalent bonds.

The mass of an atom is mainly concentrated in the nucleus.

Atomic mass refers to the mass of the entire neutral atom, which is the sum of the mass of the nucleus and the mass of the electrons outside the nucleus of the equivalent amount, and is measured in kilograms (kg) in the International System of Units. Atomic mass is divided into absolute atomic mass and relative atomic mass. Absolute mass refers to the actual mass of 1 atom and can also be called the absolute mass of an atom.

The relative atomic mass is the relative mass of the atom, that is, the mass of a carbon atom (a carbon atom with 6 protons and 6 neutrons in the nucleus, which can be simply represented by 12C) is taken as a standard, and the actual mass of other atoms is compared with it, and the value obtained is the relative atomic mass of the atom.

The chemical properties of an atom are determined by the electrons outside the nucleus of the atom, which mainly depend on the number of electrons in the outermost shell. Atoms do not have a precisely defined outermost shell, and what is commonly referred to as atomic radius is determined based on the average nuclear spacing of neighboring atoms. The chemical properties of atoms are similar to those of molecules, which are roughly as follows:

First, the mass volume is small.

Second, it is always in constant motion.

3. There is an interval between atoms.

The periodic law of atomic radius.

In the periodic table, the general trend of the radius of atoms is to increase from top to bottom and decrease from left to right. Therefore, the smallest atom is hydrogen with a radius of; The largest atom is cesium with a radius of. Because such dimensions are much smaller than the wavelengths of visible light (about 400 to 700 nm), they cannot be observed with an optical microscope.

However, using scanning tunneling microscopy, we were able to observe individual atoms.

Atomic structure and properties ** solution.

The number in the figure represents the smallest unit of indivisible positive and negative electromagnetic information - qubits (qubits) by the famous physicist John. Wheeler John Wheeler famously said, "It from bit."

After the development of quantum information research, this concept was sublimated to the point that everything originates from qubits) Note: Bits are bits.

a:nab:s

c:cl2d:h

e:cf:n

First calculate C, the formula of C =, the atomic number of F is 7 because it can form AC, so A is sodium, and then D is H

Finally, E is C (E must only have 2 layers, because there cannot be 8 P energy levels) B is S problem:

c2.Electronic type cannot be played.

2p63s2

2p54.Same as 2

When the outermost shell of an atom has less than 4 electrons, it is easy to lose electrons; When there are more than 4 and less than 8, it is easy to obtain electrons; When the outermost shell is 8 electrons, the chemical properties of the element are the most stable The chemical properties of the element are mainly determined by the number of electrons in the outermost shell of the atom, and have nothing to do with the number of electron layers, the total number of electrons outside the nucleus, and the number of neutrons, so b is correct a, c, d is wrong

Therefore, b

Episode 6: What are the chemical properties of a substance: This lesson introduces the definition of the chemical properties of a substance through three experiments: "iron rusting", "candle burning", and "copper sulfate reacts with sodium hydroxide". The properties of matter that manifest themselves in chemical changes are called chemical properties.

S area, P area, D area, DS area division principle:

S area includes the first.

All the elements of the first and second main families.

The p-zone includes elements from the 3rd to 7th main families plus zero elements.

The D region consists of elements from the third to seventh subgroups (excluding lanthanides and actinides) plus elements from the eighth group.

The DS area includes:

Elements of the first and second secondary families.

Precautions for Division:

Not all elements with a valence electron shell of ns1 or 2 are in the s region, with the exception of HE (which is in the p-region).

There are elements in the D region that do not conform to the (n-1)d1-9ns1-2 rule, e.g., 46pd 4d10.

Since the number of electrons in the outermost shell is basically the same, the number of electrons in (n-1)d is also basically the same, and the number of electrons in (n-2)f is generally different, so the chemical properties of lanthanides are similar. Actinides also have similar chemical properties.

Atomic structure refers to the composition of atoms and the way in which they are arranged internally. According to modern scientific theories, an atom is mainly composed of three elementary particles: protons, neutrons, and electrons.

1.Protons and neutrons: Protons and neutrons are located inside the nucleus of an atom and they have a relatively large mass. Protons have a positive charge, and neutrons have no charge.

2.Electrons: Electrons orbit the nucleus of an atom and move across various energy levels, or orbitals. Electrons have a negative charge and their masses are much smaller than those of protons and neutrons.

The specific structure of the nucleus of an atom and the electron cloud determines the chemical and physical properties of the element. Here are a few aspects of how atomic structure affects these properties:

The chemical properties of an atom are determined primarily by the outermost electrons in the electron cloud, known as valence electrons. These electrons are involved in the formation of chemical bonds and chemical reactions. The elements in the periodic table are arranged according to their atomic structure, especially the number of valence electrons, and elements with the same number of valence electrons usually have similar chemical properties.

The physical properties of atoms, such as density, melting point, boiling point, etc., are also related to the structure of the atom. These properties are usually related to the size of the atoms, the type of bond between the atoms, the resistance and strength of lead, and the arrangement of the atoms.

Atomic structure also plays an important role in nuclear reactions and radioactive decay. These processes involve changes in the nucleus of atoms, such as changes in the number of protons and neutrons. This results in a change in the elements (e.g., from one element to another) and often releases a large amount of energy.

Therefore, atomic structure is a fundamental factor that determines the properties of matter and chemical reactions.