How can you tell if a substance is made up of molecules, atoms, ions?

Different crystals have different constituent particles.

1. Ionic crystals.

A crystal formed by the combination of cations and anions through ionic bonds.

Common ionic crystals: strong bases, active metal oxides, most salts.

2. Atomic crystals.

All the atoms in the crystal are spatial network structures bonded by covalent bonds.

Characteristics of atomic crystals: due to the large covalent bond energy, atomic crystals generally have high melting and boiling points and great hardness, and are generally non-conductive and insoluble in common solvents.

Common atomic crystals: diamond, monocrystalline silicon, silicon carbide (emery), silicon dioxide, boron nitride (bn), etc.

3. Molecular crystals.

A solid substance made up of molecules through intermolecular forces.

Due to the weak intermolecular forces, molecular crystals are generally less hard and have a lower melting point.

Most of the inorganic compounds composed of non-metallic elemental non-metallic elements and the crystals formed by most organic compounds belong to molecular crystals.

In fact, those substances that are usually in liquid or gaseous state are composed of molecules, and the atoms inside the molecules are also covalently bonded).

4. Metal crystals.

Elemental metals and alloys. (A crystal formed by combining metal cations and free electrons with metallic bonds.) ）

In the molten state, it is the ionic compound that conducts electricity, and the molecular compound that is capable of dispersion and electrophoresis, otherwise it is the atom.

For example, sodium chloride is made up of sodium ions and chloride ions. In a substance made up of ions, only ions are present and no molecules are present.

Molecules, atoms, and ions are both particles that make up matter. Some substances, such as metals, are directly made of atoms. Salts and most alkalis, etc., are made up of ions. Most acids, most hydrides, and so on, are made up of molecules.

Generally speaking. Ionic compounds are made up of ions. It is possible that the clusters of atoms inside are connected by covalent bonds. However, as long as there is an ionic bond, it is an ionic compound. Alkali in general. Salts are all ionic compounds.

Atoms are made up of metals, usually metals, and noble gases.

Compounds that are made up of molecules are generally formed by non-metallic elements. Such as carbon dioxide. (Ammonium salts are removed.) Ammonium salt is salt. also ionic compounds).

There are also atomic crystals. It's quite special. There are not many of them, just remember them. SiO2, Si, Diamond, etc. is a covalent compound. All the atoms are connected in the form of covalent bonds.

In general, the salts that combine metal ions and acid ions are ionized sums.

Just remember the general pattern:

Most of the metal elements or ammonium containing metal elements are ionic compounds, which are composed of ions and some atomic crystals, such as SiO2, SiC, etc., which are composed of atoms, and others are mostly covalent compounds, which are composed of molecules.

Common types of crystals are:

Metallic crystals are made up of metallic bonds.

Atomic crystals are made up of covalent bonds.

Molecular crystals are made up of intermolecular forces (this is a compound made of molecules), and ionic crystals are made up of ionic bonds (this is a compound made of ions).

First of all, it is true.

This substance is considered pure.

Source! Look at the chemical formula of a substance there are several elements. 1 is elemental, and the remaining 1 is a molecular or ionic compound.

If the substance is composed of more than 1 element, and then see if there are metal elements (including ammonia) in the chemical formula of the substance, if there is any, it is an ionic compound, and if not, it is a molecule.

There is also a rule: alkalis and salts are ionic compounds, and acids and organic matter are molecular compounds. (It's just that acids ionize ions, but they're still made up of molecules).

Friend: Let me tell you a way, it is very helpful to encounter related problems in high school, 1. Any combination of atoms that can come up with a single one can be called a molecule (noble gases are monoatomic molecules), such as CO2, H2O, H2SO4, CH4, etc.;

2. Metal elements are all composed of atoms, not molecules;

3. In high school, all salts that you see containing metal ions or ammonium can be called ionic compounds, and there is no so-called "molecule" in them

To sum up: pure matter can be divided into: molecular crystals, ionic crystals, atomic crystals, metal crystals, only molecular crystals have a molecular concept.

Atomic crystals: diamond (C), crystalline silicon (Si), quartz (SiO2), emery (SiC).

The rest of the non-metallic elements and their compounds are generally molecular crystals;

The compounds of active metals are ionic crystals, and the vast majority of salts are ionic crystals.

Atomic composition:1All Noble Gases 2All Metals 3Certain solid non-metallic elementals (C, Sulfur, P, Si).

Molecular Composition:1Polyatomic molecules composed of non-metallic elements (O2, H2, N2, O3, etc.) 2Compounds composed of non-metallic elements and non-metallic elements (H2O, CO, C2H5OH, etc.).

Ionic composition: Compounds composed of metallic and non-metallic elements (NaCl, Cuo, CaCO3, etc.).

If something is placed and does not fall or decrease, it is a molecule, for example, a bowl of rice, it will become moldy and then become less, this kind of current direction.

Atoms are a bit like iron rods sharpened into needles, which are done by the outside world. You should be able to understand this way.

Molecular crystals, ionic crystals, atomic crystals, metal crystals, only molecular crystals have a molecular concept, ionic crystals are composed of cations and cations, and metallic crystals are composed of cations and free electrons.

In the molten state, substances that can conduct electricity are made up of ions, i.e., ionic compounds in the high stage.

Conversely, what cannot conduct electricity is made up of molecules, i.e., covalent compounds at the high school stage.

For example, HCl cannot conduct electricity in the molten state, so it is composed of molecules; Whereas, NaCl is in the molten state.

It is made up of ions.

If you want to see a molecular formula, you want to determine what it's made of.

Then you can try the following rules:

Most substances containing metallic elements are made up of ions. With a few exceptions, such as ALCL, which is molecular; On the contrary, most of the substances without metallic elements are made up of molecules, with a few exceptions, such as ammonium chloride (NH4Cl), which is composed of ions.

This is mine, and I hope it can help you.

goodluck

Most salts containing metal ions, and all ammonium salts, are ionic compounds, regardless of whether the anions that are salted with metal ions are organic or inorganic. For example: NaCl, C2H5ONA, sodium phenol, ammonium bicarbonate, etc., are all ionic compounds.

There are, of course, exceptions. The teacher said that there are not many metal salts in high school that are not ionic compounds, and there are generally things like: mercuric chloride, mercuric bromide, and lead acetate.

All three of these are molecular crystals.

There are also strong bases that are also ionic compounds, what potassium hydroxide, calcium hydroxide (although the solubility is not very good, but the calcium hydroxide dissolved in water is all ionized into ions) ......

Like, it's a covalent compound.

Also, regardless of whether the acid is strong or weak, all acids are not ionic compounds. Even if something as good as F2 becomes HF, it is still a weak acid, and it is only covalent.

When judging, don't care about the solubility of that thing, like BaSO4 and CaCO3, they are all ionic compounds.

That should be enough (I've told you everything I know anyway.......)I'm 2 tall now, and these are pretty much the same).