What is the main difference between molecule and atom in chemistry?

The molecule is the smallest particle that maintains the chemical properties of the substance, and the atom is the smallest particle in the chemical change, and the essence of the chemical change is the rupture of the molecule and the reorganization of the atom, that is to say, the molecule is composed of atoms, but note that the atom can also directly constitute the substance. Thank you!

The essential difference between them is that atoms are the smallest particles in chemical change, while molecules are not. That is, in a chemical change, atoms can no longer be divided, while molecules can be redivided.

Molecules are made up of atoms. With the exception of some metallic elements and noble gases, molecules are made up of multiple atoms.

Molecules change their structure in chemical reactions, while atoms do not.

A molecule is the smallest particle that retains the chemical properties of a substance, and a molecule is the smallest particle that maintains the physical properties of a substance.

A molecule is a type of particle that maintains the chemical properties of a substance; Molecules can be redivided in chemical changes. Atoms are the smallest particles in chemical change; Atoms are indivisible in chemical changes.

For example, water, chemical formula H2O.

Among them, h and o are hydrogen atoms and oxygen atoms.

H2O is the molecule of water. A water molecule is made up of two hydrogen atoms and one oxygen atom.

Because water is a covalent compound. So the existence of covalent bonds between the three atoms constitutes the water molecule.

Molecules are made up of atoms, and sometimes molecules can be atoms, such as he

The main differences between atoms and molecules are: whether they can be redivided, orders of magnitude and size, and different structures.

1. Whether it can be redivided: in chemical changes, molecules can be redivided and will change; In chemical change, atoms cannot be divided, do not become other atoms, and can only be recombined.

2. The order of magnitude is different: the order of magnitude of the general molecular diameter is 10 -10m, the molecule is very small, but has a certain volume and mass, the molecular properties of the same substance are the same, and the molecular properties of different substances are different. The order of magnitude of the atomic diameter is about 10 m.

The mass of the atom is extremely small, and the mass is mainly concentrated in protons and neutrons.

3. Different structures: molecules are composed of atoms bound together in a certain bonding order and spatial arrangement, which is called molecular structure; Atoms refer to the basic particles that are inseparable from chemical reactions, and atoms are inseparable in chemical reactions.

4. Atoms are also a kind of particles that make up matter, and atoms are constantly moving, although the atoms are small, they also have a certain mass.

5. Each molecule that constitutes a substance is consistent with the chemical properties of the substance, and the molecule can only maintain the chemical properties of the substance, but not the physical properties of the substance. Minimum is not the smallest in the absolute sense, but the minimum that maintains the chemical properties of the substance.

A substance made up of molecules, which are the smallest particles that maintain the chemical properties of a substance. Atoms are the smallest particles in chemical change;

1. From an apparent point of view, let's give an example: carbon dioxide (CO2) is composed of molecules, and CO2 can represent a molecule; Similarly, the symbols that can represent molecules are: CO, O2, HCl, H2O, H2O2, ......

Diamond (C) is made of atoms, and C can represent an atom; Similarly, the symbols that can represent atoms are: Cu, H, Cl, O, He, ......

The comparison found that in many cases, whether it is an atom or a molecule can be roughly judged by the form of "whether it is just a single element symbol".

2. Distinguish in essence, which should be illustrated by the example of hydrolysis:

As shown in the figure above, macroscopically it can represent the decomposition of water into hydrogen and oxygen under certain conditions.

On the micro level, it can be seen that water is composed of a large number of water molecules, under certain conditions, every 2 water molecules are decomposed into 4 hydrogen atoms and 2 oxygen atoms, and every 2 hydrogen atoms are combined into 1 hydrogen molecule, every 2 oxygen molecules are combined to form 1 oxygen molecule, a large number of hydrogen molecules are aggregated to form hydrogen, and a large number of oxygen molecules are aggregated to form oxygen.

It can be seen that in the process of chemical change, the type, number, and mass of atoms do not change, while the types of molecules change. At the macro level, chemical reactions are characterized by the creation of new substances, and at the micro level, the essence of chemical reactions is the differentiation of molecules and the recombination of atoms.

3. The connection between molecules and atoms: Although atoms and molecules can directly constitute matter, molecules are made up of atoms. For example, a water molecule is composed of two hydrogen atoms and one oxygen atom; A carbon dioxide molecule is made up of two oxygen atoms and one carbon atom.

1.There are gaps between molecules. For example, take 50 ml of alcohol and 50 ml of water and mix them to a volume of less than 100 ml.

2.All the molecules that make up matter are in a never-ending irregular motion. The higher the temperature, the faster the molecular diffusion, and in solids, liquids, and gases, the gas diffusion is the fastest.

Since the motion of molecules is related to temperature, this motion is called the thermal motion of molecules. For example, clothes tend to dry in the sun when it's hot.

3.The general molecular diameter is in the order of 10 -10m.

4.The molecule is small but has a certain volume and mass.

5.The molecular properties of the same substance are the same, and the molecular properties of different substances are different.

The mass of the atom is very small.

Irregular movement without stopping.

There are gaps between atoms.

The properties of the same kind of atoms are the same, and the properties of different kinds of atoms are different.

The power of the atom is very large, and the energy of the nucleus of the atom will be relatively harmful after it is released. But there is also a benefit, that is, if we are good at using it, it can help us. The radiation of the nucleus of the atom can be absorbed by the plant to reduce our damage.

But what we can usually do is try to use as little as possible with atomic energy, so that we can do less damage. It is necessary to be good at observing and keeping abreast of new methods to better prevent them.

Molecules are made up of atoms.

A molecule is the smallest particle that maintains the chemical properties of a substance; Atoms are the smallest particles in chemical change;

In chemical change, molecules can be divided into smaller particles, i.e., atoms, and atoms are no longer divisible. When a substance changes physically, only the intermolecular spacing changes, but the sub-base itself does not change. When a chemical change occurs, the molecule is destroyed and the molecule itself changes. In all chemical reactions, the types of elements, the types of atoms, the number of atoms, and the mass of atoms remain unchanged before and after the reaction.

1.The main difference between molecule and atom is that in a chemical reaction, molecules can be divided and atoms cannot be separated.

Molecules are the smallest particles that maintain the chemical properties of a substance; A molecule is generally a cluster of atoms composed of two or more atoms, and the atoms reconstitute the molecule to form a new substance, which is the essence of chemical change;

2.Atoms are the smallest particles in chemical change. We know that matter is infinitely divisible, but chemistry studies up to the atom, and the fission and decomposition of atoms is the domain of physics.

1. The size is different.

Atom: refers to the basic particles that are inseparable from a chemical reaction, and the atoms are inseparable in a chemical reaction.

Molecule: It is a whole that is bound together by the constituent atoms according to a certain bonding order and spatial arrangement, and this bonding order and spatial arrangement relationship is called molecular structure.

Proton: A proton is a subatomic particle with a positive charge of 10-19 coulombs (c), electron: the earliest elementary particle discovered.

Quantum: If there is the smallest indivisible fundamental unit of a physical quantity, the physical quantity is quantized, and the smallest unit is called quantum.

Particle: refers to the smallest component of matter that can exist in a free state.

2. The composition is different.

Atom: An atom is made up of a nucleus and electrons that move around the nucleus.

Molecule: A molecule is composed of atoms, which are combined into atoms in a certain order and arrangement through a certain force.

Protons: Protons belong to the baryon class and are made up of two upper quarks and one lower quark through gluons under strong interaction.

Electrons: All atoms are made up of a positively charged nucleus and a number of electrons moving around it.

Quantum: An indivisible and fundamental entity.

Particles: Different particles, made up of different compositions.

Particle discovery journey.

In 1897, Thomson discovered the electron, and in 1911, Rutherford proposed the nuclear structure of the atom. Then we discovered photons, and thought that "photons, electrons, protons, and neutrons" were indivisible particles that made up matter, so we called them "elementary particles".

At the end of the 19th century, atoms were considered to be the smallest microcode particles that make up matter. After the discovery of electrons, protons, and neutrons, many people thought of photons and them as "elementary particles" that make up matter.

Hundreds of new particles that are not composed of protons, neutrons, and electrons were gradually discovered; It was also discovered that protons, neutrons, etc., also have their own complex structures. Since the second half of the 20th century, the word "basic" has been removed and collectively referred to as particles.

Since the 30s of the 20th century, some new particles have been discovered in the study of cosmic rays.

In 1932, the positron was discovered;

In 1937 the child was discovered;

In 1947, the k-meson and meson were discovered;

Later, some particles were also discovered that have a mass greater than the mass of a proton, called hyperons.

The fundamental difference between a molecule and an atom is that in a chemical change, the molecule can be redivided and the atom cannot be divided.

A molecule is the smallest particle that exists independently and maintains the chemical properties of a substance, and is a whole that is bound together by the constituent atoms according to a certain bonding order and spatial arrangement, and this bonding order and spatial arrangement is called molecular structure. Due to the interaction between atoms within a molecule, the physical and chemical properties of a molecule depend not only on the type and number of constituent atoms, but also on the structure of the molecule.

Atoms form the basic units of chemical elements and the smallest particles in chemical change, that is, particles that cannot be redivided by chemical change, consisting of the nucleus and electrons moving around the nucleus. Atoms make up the smallest unit of matter in general, known as elements. There are 119 known elements.

Hence has a nuclear structure.