A compound is composed of two or more elements chemically bonded together in fixed proportions that can be represented by a chemical formula. Compounds have distinct properties such as melting and boiling points and are either formed by the release or absorption of energy. Common examples of compounds include water, carbon dioxide, sodium chloride, and calcium carbonate.

1. Compounds
A compound is a pure substance
composed of two or more
elements, combined chemically in
a definite proportion by mass.
Characteristics
Pure and homogenous
Have definite melting and
boiling points.
During formation, energy is
either absorbed or released.
Definite chemical formulae
Are neutral unlike
radicals
Carbon + Oxygen → Carbon dioxide (CO2)
Sodium Chloride (NaCl), Magnesium
Oxide (MgO),
Marble and Chalk (CaCO3),
Hydrochloric Acid (HCl), Potassium
Hydroxide (KOH), Sand (SiO2),
Baking Soda (NaHCO3)
Constituents can
be separated by
only chemical
methods.
Examples :
Hydrogen + Oxygen → Water (H2O)