Question

A dinegatively charged ion has the same number of protons and neutrons. Its mass number is 32. The number of electrons in the ion is

• A. 18
• B. 16
• C. 14
• D. 20

Answer 1

The correct option is A

18

The explanation for the correct option:

1. The element with mass number 32 is Sulfur. Its atomic number is 16.
2. The electrical configuration of sulfur is 2,8,6. To have a stable outer shell, it needs to gain two more electrons.
3. Sulfide ions (S^2-) will have two more electrons than protons and will have a negative charge as a result.
4. The number of protons, positively charged, massive fundamental particles, present in the sulfur nucleus is indicated by the atomic number Z. The sulfur atom is defined as a sulfur atom by this number.
5. If there are 16 positive nuclear charges in a neutral atom, there must be 16 negatively charged particles, or electrons, whirling about the nucleus.
6. Because electrons have such a little mass, the sulfur nucleus must have 16 neutrons, or neutrally charged, heavy fundamental particles, to account for the isotope's mass.
7. Sulfur accepts two electrons to form Sulphide ions.
8. Thus, ${\mathrm{S}}^{2-}$ ion, on the other hand, has 18 electrons, 16 protons, and 16 neutrons.

Hence, the correct option is (a).