Ncert Exercises & Solutions

Electronic configuration of a transition element X in +3 oxidation state is [Ar] $3 d^{5}$ . What is its atomic number?

1. 25

2. 26

3. 27

4. 24

NEETprep Answer: (b) Electronic configuration of

X^{3 +}

is [Ar]

3 d^{5}

it repersents the total number of e® and oxidation state.Therefore, atomic number of X = 18+ 5+ 3=26 Hence, option (b) is correct.