Answer:
13 u.
Explanation:
Atoms is the small part of an element that contains protons, electrons and neutrons. The electron revolve around the nucleus and protons and neutrons are present inside the nucleus.
Atomic mass of an element may be defined as the sum of protons and neutrons.
Atomic mass = No. of protons + No. of neutrons
Atomic mass = 6 + 7
Atomic mass = 13 u.
Thus, the atomic mass of an element is 13 u.
