Question

From the symbol $${\phantom{A}}_{\phantom{2}}^{\phantom{4}}{\phantom{A}}_{\phantom{2}2}^{\phantom{2}4}\mathrm{He}$$ for the element helium, write down the mass number and the atomic number of the element.

Answer 1

$${\phantom{A}}_{\mathrm{Atomic}\mathrm{number}}{\phantom{A}}_{\phantom{2}}^{\phantom{4}}{\phantom{A}}_{\phantom{2}2}^{\phantom{2}4}\mathrm{He}{\phantom{A}}^{\mathrm{mass}\mathrm{number}}$$

• Mass number – 4
• Atomic number – 2