Answer : An atom with 7 protons, 6 neutrons, and 7 electrons has an atomic mass of 13 amu.
Explanation :
As we are give that,
Number of protons = 7
Number of electrons = 7
Number of neutrons = 6
As we know that,
Atomic number =Number of protons = Number of electrons = 7
Atomic mass = Number of neutrons + Atomic number
Atomic mass = 6 + 7 = 13 amu
Therefore, the atomic mass is, 13 amu