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. 41257
• B. 41985
• C. 14, 12, 12
• D. 41255

Answer 1

Answer: (A)

41257

Answer 2

Isotopes are nuclei that have same atomic number but different atomic mass. $\therefore$ Atomic number of the isotope $=12$ $\Rightarrow$ Number of electrons and protons $=12$ Number of neutrons $=$ At. mass $-$ Atomic no. $=26-12=14$