Question

Describe the representation of an element and a compound using a chemical formula.

Answer 1

Chemical formula:

• chemical formula represents one molecule of an element or a compound.
• The chemical formula for an element is represented by the symbol of the element followed by its atomicity in subscript.
• For example the chemical formula of Calcium is (Ca), Magnesium is (Mg), and Silver is (Ag).
• The chemical formula for a compound is represented by the symbol of each element followed by the number of its atoms present in one molecule, written in the subscript.
• When the number of atoms of an element in the molecule is one, the subscript is not written.
• For example the chemical formula of water is (${\mathrm{H}}_2\mathrm{O}$ ), carbon dioxide (${\mathrm{CO}}_2$ ), and sodium chloride are ($\mathrm{NaCl}$ ).