Question

What is effective nuclear charge and the periphery of nitrogen atom when an extra electron is added in the formation of an anion?

• A. 1.20
• B. 2.45
• C. 3.55
• D. 5.95

Answer 1

Answer: (C)

When an extra electron is added in nitrogen atom, added electron will be screened by five electrons in second orbit $\left(2s^{2}2p^3\right)$ and two electrons in first orbit $\left(1s^2\right)$

Now screening constant, $\sigma =5\times 0.35$ in $n$ th orbit $+2\times 0.85$ in $(n-1)$ th orbit
$=1.75+1.70=3.45$
$\therefore$ Effective nuclear charge $=7-3.45=3.55$