Question

An α-particle has all the given properties, except

• A. it has +2 charge
• B. it has mass of 4 u
• C. it has no electron
• D. it is double positively charged magnesium cation

Answer 1

The correct option is D it is double positively charged magnesium cation

An α-particle is a double positively charged helium ion $\left(H{e}^{2+}\right)$. It consists of two protons, two neutrons and no electron. It has a mass of 4 u.
A double positively charged magnesium cation is represented as $M{g}^{2+}$. It consists of twelve protons, twelve neutrons and ten electrons.
Hence, the correct answer is option (d).