Question

If magnesium atom having atomic number 12 has an isotope with mass number 26, then the number of protons, neutrons and electrons respectively of the atom are

(a) 12, 14, 12

(b) 12, 12, 14

(c) 14,12, 12

(d) 12,12, 12

Answer 1

Correct option (a) 12, 14, 12

Explanation:

lsotopes are nuclei that have same atomic number but different mass number.

∴ Atomic number of the isotope = 12

⇒ Number of electrons and protons = 12

Number of neutrons = Mass no. - Atomic no.

=26 - 12 = 14