As a ca atom undergoes oxidation to ca2+, the number of neutrons in its nucleus
(1) decreases
(2) increases
(3) remains the same

Hence the correct answer is remains the same

Explanation:

As a Ca atom undergoes oxidation to Ca2+,as follows:

Ca --- Ca 2+ + 2e-

In the process of oxidation calcium loss 2 electron only there is no change in the number of protons as well neutrons therefore there is no change in the number of neutrons in its nucleus

Hence the correct answer is remains the same

Oxidation:

Oxidation is a process in which either 1 or all following changes occurs:

1.Gaining of oxygen atoms

2.Loss of electrons

3.Loss of hydrogen atom.

4.Increasing oxidation number.

Reduction:

Reduction is a process in which either 1 or all following changes occurs:

1.Loss of oxygen atoms

2.Gaining of electrons

3.Gaining of hydrogen atom.

4.Decreasing oxidation number.

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter  

i think is conclusions.i think so