Question

Atomic mass of an element is the sum of the number of _____and____

Answer fast exam going on please I beg

Answer 1

Answer:

For any given isotope, the sum of the numbers of protons and neutrons in the nucleus is called the mass number. This is because each proton and each neutron weigh one atomic mass unit (amu). By adding together the number of protons and neutrons and multiplying by 1 amu, you can calculate the mass of the atom.

Answer 2

Answer:

It is not good to cheat in exam but here is your answer

Explanation:

Because the sum of the numbers of protons and neutrons equals the mass number, 127, the number of neutrons is 74 (127 − 53 = 74).