What is the microscopic essence of physical change?

The essence of physical change is that the molecular interval of matter changes, the composition and structure of matter do not change, and no new matter is generated.

A physical change is simply a change in the distance between the molecules, and no new matter is formed.

The number and size of molecules do not change when a substance composed of molecules changes physically, but only the spacing and arrangement between molecules change.

Molecular movement. The molecular structure has not changed.

The form of matter has to be transformed.

No new matter is generated.

From a microscopic point of view, the essence of the chemical reaction of Laliang is that the molecule is broken into atoms, and the atoms are reconstituted into new molecules, and the types and numbers of atoms remain unchanged before and after the chemical change, and the types of molecules must change.

Chemical changes are always accompanied by physical changes. In the process of chemical change, there are usually luminescence, exothermia, and endothermy. According to the atomic collision theory, the chemical change between molecules is accomplished through collision, and two conditions need to be met to complete the collision of the molecule that reacts

Have sufficient energy; Correct orientation.

Because the reaction needs to overcome a certain molecular energy barrier, it must have a higher energy to overcome the molecular energy barrier. Two colliding molecules must have a positive orientation for the old bond to break.

Chemical changes can be divided into four basic types of reactions based on the types and quantities of reactants and products: chemical reactions.

Decomposition reactions, displacement reactions, and metathesis reactions.

Oxidation reactions. Reducing agents (reactants) lose electrons or share electron pairs that deviate from valency.

Elevated is oxidized and an oxidation reaction occurs to produce oxidation products.

Reduction reaction. Oxidants (reactants) gain electrons or share electron pairs biased valency decreases to be reduced Reduction reaction occurs to generate reducing products.

In a chemical reaction, a reaction in which the total amount of reactants is greater than the total energy of the products is called an exothermic reaction. These include combustion, neutralization, metal oxidation, thermite reactions.

A reaction between a more active metal and an acid, a reaction from an unstable substance to a stable substance.

Physical change: macroscopic: there is no change in the formation of new matter, that is, only the form of the substance has changed, and the substance itself has not changed, such as water from liquid pure to gaseous water vapor.

Microcosm: The type of molecule itself remains the same, but the gap between the molecules changes.

Chemical Changes: Macroscopic: There are changes in the formation of new substances, such as iron selling rust, which turned out to be iron, and rust is no longer iron.

Microscopic: There are changes in the formation of new molecules, such as hydrogen burning in oxygen, which was originally hydrogen molecules and oxygen molecules, and then reacted to form new water molecules.

The microscopic essence of physical change: the particles that make up matter do not change in themselves, i.e., molecules and atoms.

When the matter only changes in state, the molecules that make up the substance will not change, but the distance between the molecules has changed, and when the general substance changes from solid to liquid, the distance between the molecules becomes larger; When moving from a liquid state to a gaseous state, the distance between molecules increases by a factor of about ten. In short, a physical change is a change in the distance between molecules.

High-quality answers. Physical changes include gasification, liquefaction, sublimation, condensation, and so on.

The microscopic angle is due to the increase in temperature, the acceleration of the movement of molecules inside the substance, so that the distance between each other increases, and the gravitational pull between the atoms (molecules) is freed, and they are separated from each other.

For example, gasification is the fact that the molecules in the liquid state have enough energy due to boiling, and they change from a relatively compact form to a relatively loose form in the gaseous state.

Physical change is generally the change of the state of the substance, when the substance only changes the state, the molecules that make up the substance will not change, but the distance between the molecules has changed, and the general substance changes from solid to liquid state, and the distance between molecules becomes larger; When moving from a liquid state to a gaseous state, the distance between molecules increases by a factor of about ten. In short, a physical change is a change in the distance between molecules.

The microscopic essence of chemical change: the particles that make up matter themselves change, the molecular nucleus is divisible, and the atom is inseparable. Atoms reconstitute new molecules, and new molecules make up new matter.

The microscopic abyss is the macrocosm, and the macroscopic abyss is the microcosm. The microscopic limit large convergence constitutes the extended universe, the macroscopic limit small convergence constitutes the curled up universe, and the extended universe and the curled up universe constitute the entire universe. Expand, curl up as a definition, not a directional action word, can be defined as expand to curl up, curl up as an extension.

There is no change in the formation of new matter (macroscopic).

There is no change in the molecule itself (microscopic).

The essence is that the smallest particle itself remains unchanged in the first mathematical properties of materialization, except that the spaced motion between the particles changes, and no new matter is generated. A physical change is a change in which no new matter is formed, but only a change in the shape and state of the substance.

Physical change refers to the fact that although the state of matter has changed, generally speaking, the composition of the substance itself has not changed. For example, the change of position, volume, shape, head temperature, pressure, and the mutual conversion between gaseous, liquid, and solid states.

There are also the interaction between matter and electromagnetic field, the interaction between light and matter, and the interaction and transformation between microscopic particles, all of which are physical changes.

The basic three-state change of matter, and no new substance is produced, so it belongs to physical change. For example: deliquescent of alkali, melting of ice, crushing of bile alum, etc.

The flame color reaction is a physical change. The flame reaction is a change in the energy level of electrons inside the atoms of a substance, which is commonly known as the change in the energy of electrons in an atom, and does not involve a change in the structure and chemical properties of matter.