Question

Match the elements with its atomic mass:

• A. 27
• B. 23
• C. 16

Answer 1

Atomic mass is defined as the total sum of protons and neutrons present in an atom.
Aluminium is made up of 13 protons and 14 neutrons. Hence, its atomic mass is 27 u.
Sodium is made up of 11 protons and 12 neutrons. Hence, its atomic mass is 23 u.
Oxygen is made up of 8 protons and 8 neutrons. Hence, its atomic mass is 16 u.