Question

Identify the ${\mathrm{Mg}}^{2+}$ ion from Fig. where $\mathrm{n}$ and $\mathrm{p}$ represent the number of neutrons and protons respectively.

• A.

  

• B.

  

• C.

  

• D.

  

Answer 1

The correct option is D

Explanation:

Calculating the number of electrons:

• The atomic number$\left(\mathrm{Z}\right)$ of Magnesium is 12.
• The atomic number is the number of protons present in an atom, that is the number of protons is 12
• In the neutral state, the number of electrons is equal to the number of protons, that is the number of electrons is 12.

Calculating the number of protons:

• The mass number$\left(\mathrm{A}\right)$ of Magnesium is 24.
• The mass number is the sum of the number of protons and neutrons.
• Therefore, the number of neutrons is $24-12=12$

Calculating the number of electrons is ${\mathrm{Mg}}^{2+}$ ion:

• In ${\mathrm{Mg}}^{2+}$ , Magnesium having +2 charge which means magnesium loses 2 electrons.
• Therefore, the number of electrons is $12-2=10$.
• In Option D there are 12 neutrons, 12 protons, and 10 electrons.

Therefore, the correct answer is option (D)