Element, Atom and Molecule Ions IonicMolecular Compound

 He  👉   Atom ,  Pure element

H2  👉  Molecule , Pure Element

H2O   👉  Molecule , Compound

Molecule is made up of DIFFENT many atom. 

Compound is made up of different atom

NOTE: ALL MOLECULE ARE NOT COMPOUND,  ALL COMPOUND ARE MOLECULES

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A molecule is a group of two or more atoms held together by chemical bonds. A compound is a substance which is formed by two or more different types of elements which are united chemically in a fixed proportion.

When two or more atoms join together, we call it a molecule. When two or more atoms of different elements join together, we call it a compound. All compounds are molecules, but not all molecules are compounds.

There is one Atom  in Element

An atom is the part of an element. A particular element is composed of only one type of atom. Atoms are further composed of subatomic particles called electrons, protons and neutrons.

Atom is electrical neutral - contain same number of protons and electron

Ions - contain different number of protons and electron

                    Negative IONS -   Anion

                    Positive IONS -   Cation

There is :- 

Ionic Compound 

Covalent Compound | Molecular Compound

Ionic Compound - made up metal and 99% non metal Example NaCl  = Na-Metal Cl-Non-Metal

Electron are not shared , are transfered electron. Example Contain positive and negative charge is

 Na⁺

Cl^-

Covalent Compound - made up of non metal Example H2O  = H-Non-Metal O -Non-Metal

In Molecular Compound electron are shared between Atom.

Examples:

CO 👉  Molecular  

Why C - Non-metal and O - Non-metal

MgCl₂ 👉  Ionic

Why Mg - Metal and Cl₂ - Non-metal

SF6 👉  Ionic

Why S - Non-Metal and F6 - Non-metal

CaO 👉  Ionic

Why Ca - Metal and O - Non-metal

But be Careful

NH4 Cl 👉  Ionic

Why NH4⁺ - Non-Metal and  Cl^-     - Non-metal

Ionic Compound are (usually) formed when a metal reacts with a nonmetal (or a polyatomic ion).