Question

An atom is determined to contain 12 protons, 10 electrons, and 12 neutrons. What are the mass number and charge of this atom or ion?
Select one:
a. mass number: 24, charge: +2
b. mass number: 22, charge: neutral
c. mass number: 34, charge: -2
d. mass number: 34, charge: +2

Answer 1

Mass number= atomic number + number of  neutrons.
A=Z+N
Z=number of protons=12
N=12

A=12+12=24

If, we have 12 protons and 10 electrons, the charge of this ion is +2

Therefore: mass number:24; charge: +2

Answer: a. mass number: 24; charge: +2