The problem of molecular atoms. Atomic and molecular issues

Atoms include positively charged nuclei and negatively charged electrons (extranuclear electrons), and nuclei include uncharged neutrons that are positively charged protons

The reason why atoms are not charged is that the positive charge carried by the nucleus is equal to the negative charge carried by the electrons outside the nucleus, and the electrical properties are opposite and cancel each other out

In atoms, the number of nuclear charges, the number of protons, the number of electrons outside the nucleus, and the main mass of the atom is mainly concentrated in the nucleus (special case: hydrogen atoms have no neutrons).

Relative atomic mass (in units of 1) Number of protons Number of neutrons Thomson discovered the electron and Rutherford discovered the nucleus

Oh, do you have Q, I just learned this, let's talk about it, there are protons and neutrons in the nucleus, and there are electrons outside the nucleus.

Proton positive electrons are negatively charged

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Number of protons + number of neutrons = number of nuclear cores.

Protons are positively charged, neutrons are uncharged, and electrons outside the nucleus are negatively charged.

Hello. The mass number is the one on the top left of the element.

Mass number = number of protons + number of neutrons.

The number of protons is the one on the left side of the element.

Extranuclear electrons = number of protons.

Number of neutrons = number of masses - number of protons.

Protons are positively charged.

Electrons outside the nucleus are negatively charged.

Hope it helps. 3q

Number of protons = number of nuclear charges.

Number of protons + number of neutrons = number of masses.

The number of protons of an atom is equal to the number of electrons.

Protons are positively charged, and nuclei are positively charged.

The electrons are negatively charged.

The atom is composed of the nucleus and the electrons outside the nucleus, the nucleus is composed of protons and neutrons, the protons are positively charged, the neutrons are not charged, the electrons outside the nucleus are negatively charged, and the electrons outside the proton nucleus are charged equally, and the electrical properties are opposite, so the atoms are neutral. The number of protons plus the number of neutrons is equal to the number of electrons outside the nucleus, and the number of protons is also called the number of nuclear charges, which is equal to the number of electrons outside the nucleus.

1.Gasoline combustion is a chemical change, and the molecule itself changes.

Gasoline volatilization is a physical change, the molecule itself does not change, but the interval changes.

2.Part of the upper bottle turns red.

Both bottles turned red.

Chemistry is written: in constant motion.

In the physics books, it is: making random changes that never stop.

The composition of a substance is judged by which structures it is directly composed of, for example, water is directly composed of water molecules that are directly connected by intermolecular interactions (orientation forces, induction forces, dispersion forces, hydrogen bonds). The water molecule is composed of two hydrogen atoms and one oxygen atom through covalent bonding, the role of covalent bonds is much greater than the intermolecular interaction, the ice melts, the water evaporates and boils to destroy the intermolecular interaction, the essence of water has not changed, it is still a water molecule, and the electrolysis of water into hydrogen and oxygen is equivalent to breaking the covalent bond of hydrogen atoms and oxygen atoms. So we say that water is made up of water molecules.

There is no such thing as an iron molecule in iron, only iron atoms, to be precise, iron atoms lose some electrons to become positive ions, and then immerse themselves in a sea of free electrons (electrons lost for iron). It is the interaction between the positive ions and the electrons that are glued together to form iron. This is also the reason why iron is electrically conductive, malleable.

If we want to figure out whether some unknown substances are made up of molecules, atoms or ions, we have to rely on experiments to prove it. You only need to memorize the composition of specific substances and it will naturally draw inferences.

Molecular atoms: one. Molecule.

A molecule is a type of particle that makes up matter.

Most substances are made up of molecules. For example, oxygen is made up of oxygen molecules; Water is made up of water molecules; Sulfuric acid is made up of sulfuric acid molecules, etc.

A molecule is the smallest particle that maintains the chemical properties of a substance.

1) "Keep" means that each molecule that makes up a substance has the same chemical properties as that substance. For example, the smallest particle that maintains the chemical properties of oxygen is the oxygen molecule.

2) The properties of matter have physical properties and chemical properties, and molecules can only maintain their chemical properties, and cannot be said to be properties of substances, because the physical properties of substances (such as melting point, boiling point, hardness, density, etc.) are all properties of a large number of molecular aggregates of the substance. For example, liquid oxygen formed by the aggregation of a large number of oxygen molecules is pale blue.

3) Molecules are made up of atoms. For example, 1 oxygen molecule is made up of 2 oxygen atoms. Two. Atom.

An atom is also a type of particle that makes up matter.

Metals, noble gases, diamonds, and graphite are all substances that are directly composed of atoms. For example, mercury is made up of mercury atoms, and helium is made up of helium atoms.

Atoms are the smallest particles in chemical change. In a chemical reaction, a molecule can be divided into atoms, but the atoms can no longer be divided into smaller particles in the chemical reaction, but the atoms are recombined into new molecules, which is the essence of chemical reactions. For example, when red mercury oxide is heated, the mercury oxide molecule is decomposed into oxygen atoms and mercury atoms, and every 2 oxygen atoms combine into 1 oxygen molecule, and many mercury atoms aggregate into metal mercury.

Generally, in chemistry, there is no such thing as fusion, fission, etc., that is, atoms are unchanging.

The meaning of the first sentence is that an atom is the smallest unit in a chemical reaction that does not change. A chemical reaction is just a change in the way atoms are combined, but the atoms themselves do not change.

In the second sentence, chemical annihilation properties generally refer to properties such as flammability, toxicity, and chemical reaction with certain substances, which can be summarized as properties involving chemical changes. The physical properties generally refer to density, melting point, boiling point, color, phase (gas-liquid-solid), etc., and do not involve chemical reactions.

For example, carbon monoxide CO, which is combustible, reacts with oxygen and ignites to form CO2. Here, the atoms are C and O, and the molecules are Co, O2, and the resulting CO2

CO and O2 have a chemical reaction, and the atoms (C, O) are rearranged and combined, so that they are not flammable and non-toxic, that is, through the chemical reaction, the CO molecule becomes a CO2 molecule, and the chemical properties have changed (the molecule is the smallest particle that maintains the chemical properties of the substance), but in this process, the carbon and oxygen atoms themselves have not undergone wide modification changes.

You're asking very carefully.

Hello, the question you are asking is a conceptual one.

Atoms are divided into free states and atoms in chemical states. Atoms in their free state do not form chemical bonds with any other atoms. "A molecule is made up of atoms", then there must be no free atoms in the molecule.

If there are free atoms in a molecule, the whole system is still two substances!

Once an atom is involved in the formation of a molecule, it must be in a chemical state and needs to form chemical bonds with other atoms. Chemical bonds are divided into ionic bonds, covalent bonds, etc., and which type of chemical bond is formed is related to the nature of the atom. If the bonding process involves the gain or loss of electrons, the atom will become ionic and the ionic bond will be formed.

For example, the sodium atom and the oxygen atom react between the two to form the compound sodium oxide, and the result is that the oxygen atom gains electrons to form oxygen ions, and the sodium atoms lose electrons to form sodium ions, and ionic bonds are formed between the two. That is, in sodium oxide, there are only oxygen ions and sodium ions, and there are no oxygen and sodium atoms.

If there is only a shift between the two nuclei of electron pairs in the bonding process, and there is no complete electron gain or loss, and the atom does not become an ion, then a covalent bond is formed. For example, carbon dioxide, the carbon atom does not lose electrons to form carbon ions, and the oxygen atom does not gain electrons to form oxygen ions, so it can be said that carbon dioxide is made up of carbon atoms and oxygen atoms!

A water molecule consists of one oxygen atom and two hydrogen atoms, an ozone molecule consists of 3 oxygen atoms, a carbon dioxide molecule consists of one carbon atom and two oxygen atoms, and a glucose molecule consists of one oxygen atom, 6 carbon atoms, 12 hydrogen atoms.

So a molecule can be made up of different atoms.

Molecules are also like oxygen molecules, which are made up of two oxygen atoms.

Molecules can have different atomic compositions, such as water molecules, which are composed of oxygen atoms and two hydrogen atoms.

When discussing why atoms can bind into molecules, and why ions combine into compounds, it is necessary to involve the electronic action that binds atoms together—chemical bonds. The two basic types of chemical bonds are ionic bonds and covalent bonds, ionic bonds are formed by the transfer of electrons between atoms, and covalent bonds are formed by common electron pairs between atoms.

Inorganics are mostly compounds formed by ionic bonds. For example, NaCl is a typical ionic compound, in a NaCl crystal, each Na+ is surrounded by 6 Cl-, and similarly, each Cl- is surrounded by 6 Na+. The formula "nac" l only means that there are equal amounts of positive and negative ions in the recrystal.

The atoms of organic matter China are mainly bound by covalent bonds. Generally speaking, the number of unpaired electrons outside the nucleus of an atom is the number of covalent bonds that the atom may form. For example, the outer shell of the H atom has only one unpaired electron, so it can only combine with two H atoms or one other monovalent atom to form a diatomic molecule, and can no longer bind to the second atom, which is the saturation of a covalent bond.

You're talking about molecular electron sharing. This is present in covalent compounds, such as in HCl, where electron pairs are shared between H nuclei and Cl atoms, rather than favoring one atom over another. This one is related to the electron gain and loss capacity of the atom.

Atoms are particles that are smaller than the fraction, and molecules can be obtained by combining them with each other;

Atoms obtain ions by gaining and losing electrons, and ions can directly form compounds;

Atoms, molecules, ions can all be directly constituted into matter).

The outermost electrons of the atom are not saturated, and the atoms are generally combined with covalent bonds to obtain molecules;

Atoms become ions or form roots by gaining and losing electrons, and ions form compounds through ionic bonds;

The landlord has a strong ability to find problems and question, which is commendable. This is the first and most important step in creation, and the following is to analyze the problem and solve it. However, this problem may be too difficult for junior high school students to solve on their own for the time being.

This question can be understood in several ways.

1.When we say that the irregular motion of a molecule means that it is impossible to give the equation of motion of a molecule according to the previous state of motion, as is the case with a macroscopic object, so that the subsequent state of motion can be determined. However, it is not denied that the molecule has a definite position at a certain moment, which is why it is possible to "photograph" the molecule with an electron microscope.

2.The irregular motion of the molecule is the movement of the molecule as a whole, and the atoms inside the molecule are connected by chemical bonds, with a relatively fixed spatial arrangement, and the ** of the benzene molecule reflects this relatively fixed arrangement. If you carefully measure the bond length between carbon atoms, you will find that they are not exactly equal as they are theoretically possible, but are large and small, which is evidence that carbon atoms are vibrating small all the time.

The chemical bonds that connect the carbon atoms are very strong (like a very hard, invisible spring), which makes this vibration relatively weak. If it is a rare gas, a monoatomic molecule, there is no chemical bond between the atoms, and the movement of the atoms is relatively free. If you take a picture of benzene vapor in the same way, you will see that there are many benzene molecules arranged in a disorderly manner, and the atoms inside the benzene molecule are still regularly arranged.

3.Whether the molecular atoms are arranged in order depends on two factors at the same time, one is the gravitational force between the molecular atoms, and the other is the strength of the thermal motion. The greater the gravitational pull, the more neatly the molecular atoms tend to be aligned, and the strength of the thermal motion depends on the temperature, the higher the temperature, the more chaotic the arrangement becomes.

4.Textbooks often say that molecular atoms are constantly in violent thermal motion, and this intensity is relative, not really violent in any situation, it is more violent in gases, but not so intense in solid liquids. When the gravitational force is high and the temperature is low, the thermal motion is less violent, and when the temperature is very low, the thermal motion tends to stop (but it will never stop, and there are still molecular atoms vibrating and molecular rotation at absolute zero).

5.The gravitational force between the silicon atoms and the atoms of the matrix material can be as large as chemical bonds (depending on whether the atoms are close enough to each other), and the thermal vibration can often be reduced by means of low temperatures, so that the silicon atoms can be relatively neatly aligned.

That's the electron microscope**, and the frequency of atomic motion is not necessarily too large, so it can't be seen.

Because the electrons outside the nucleus rotate around the nucleus at high speed, they do not stick together.

Because the electrons outside the nucleus are orbiting the nucleus at high speed, they do not attract each other.