Define mono-valent, divalent and trivalent elements with example

The combining capacity of an atom is known as its valency. The number of bonds that an atom can form as part of a compound is expressed by the valency of the element.

Monovalent

An atom, ion, or chemical group with a valence of one, which thus can form one covalent bond is called monovalent.

Examples

Atoms that are monovalent are

• Hydrogen
• Lithium
• Sodium
• Chlorine

Divalent

An atom, ion, or chemical group with a valence of two, is called divalent.

Examples

Atoms that are divalent are

• Beryllium
• Oxygen
• Magnesium
• Sulphur

Trivalent

An atom, ion, or chemical group with a valence of one, which thus can form one covalent bond is called monovalent.

Examples

Atoms that are trivalent are

• Boron
• Nitrogen
• Aluminium
• Phosphorous