Respuesta :

arthurpdc

The atomic mass is equal to the sum of the number of protons and neutrons. Then, it is [tex]p+n = 4+5=9[/tex].

Hence, the answer is 9.

plushdna

Name:  Beryllium

Atomic Mass:   9.012 atomic mass units

Number of Protons:  4

Number of Neutrons:  5

Number of Electrons:  4

hope it helps

-Plushdna