What makes up the atomic mass? a : neutrons
b : electrons + neutrons
c : protons + neutrons
d : electrons + protons

hi, your answer is c : protons + neutrons

atomic mass of an atom is sum of masses of it's protons and neutrons.

10/60

step-by-step explanation:

if you divide 10 by 60 the answer is 0.166666 while if you divide or solve the other problems it equals 0.6

ratio is 2 : 9

the answer is three

13.5 : 3