Question

Atomic number and mass number of an element M are 25 and 52 respectively. The number of electrons, protons and neutrons in M²⁺ ion are respectively-
1. 25, 25 and 27
2. 25, 27 and 25
3. 27, 25 and 27
4. 23, 25 and 27

Answer 1

Correct Answer - Option 4 : 23, 25 and 27

Explanation:

• In any chemical reaction, there is only a change in the number of electrons occur, the number of proton and neutron remains unchanged.
• In the formation of cation, electrons are removed.

M → M²⁺ + 2 e^-

• In the formation of anion, electrons are gained.

M + 2 e^- → M^2-

• In any atom Atomic number (Z) = Number of protons.

Z = P

• Atomic mass (A) = Number of Neutron + Number of proton.

A = N + P

In the formation of M²⁺, two-electron removed.

Number of electron = 25 - 2 = 23 electron.

The number of proton = 25.

Number of neutron = A - Z = 52 - 25 = 27.

So, The number of electrons, protons and neutrons in M²⁺ ion are respectively 23, 25 and 27.