Answer:
The correct answer is: Atomic mass= 26
Explanation:
The atomic mass is given by the addition of the number of protons and neutrons. Protons and neutrons are located in the nucleus of the atom and are considered as the subatomic particles with higher mass. So, the masic number of an element is denoted as A and is calculated as follows:
A= number of protons + number of neutrons = 15 + 11= 26
