Question

The atomic number of magnesium is 12. How many protons are there in the nucleus of magnesium atom? How many electrons and protons does an ion of magnesium which has a charge of +2 contain.

• A. 10, 10
• B. 10, 13
• C. 11, 12
• D. 10, 12

Answer 1

The correct option is D 10, 12

The atomic number (Z) of magnesium atom = 12
For neutral atom, Number of protons (p) = Number of electrons (e) = atomic number (Z)
i.e Number of protons in the nucleus of Magnesium atom = 12
Now, for $M{g}^{+2}$number of electrons = 12 -2 = 10
and the number of protons remains the same i.e 12
Thus, the correct answer is 10, 12