MCQ
An anion $A ^{3-}$ has 18 electrons. Write the atomic number of A.
- A24
- B21
- C12
- ✓15
✓
Answer
Correct option: D.
15
(d) 15
Explanation: $A ^{3-}$ means it has got an additional 3 electrons. The atomic number is the number of electrons in a neutral atom.
Therefore atomic number $=18-3=15$.
Explanation: $A ^{3-}$ means it has got an additional 3 electrons. The atomic number is the number of electrons in a neutral atom.
Therefore atomic number $=18-3=15$.
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