Atoms and Molecules – Notes

Atoms and Molecules 

Matter is made of tiny indivisible particles.

In any chemical reaction, the total mass of the substance before and after the reaction is the same although its matter undergoes a physical change.

Molecule is the combined state of atoms.

Number of atoms constituting a molecule is atomicity.

Cation is a positively charged particle in a molecule.

Negatively charged particle in a molecule is known as anion.

Combining capacity of an element is known as valency.

Formula is a short hand representation of a molecule.

For writing a formula a set of rules are followed.