Please help me with chemistry

Question

Determine the Mass Number of the Following Elements: 

1. Al - 13 Protons 15 Neutrons

1. B - 5 Protons 6 Neutrons

1. C - 6 Protons 8 Neutrons

1. Sc - 21 Protons 25 Neutrons

Na - 11 Protons 13 Neutrons

Answer 1

The mass number is the sum of protons & neutrons.

Al - 13 Protons 15 Neutrons--> Mass number = 28

B - 5 Protons 6 Neutrons --> Mass number = 11

C - 6 Protons 8 Neutrons --> Mass number = 14

Sc - 21 Protons 25 Neutrons --> Mass number = 46

Na - 11 Protons 13 Neutrons --> Mass number = 24