Question

Element with atomic number $115$ has configuration as _______ and with most stable cation as ________.

• A. $\left[Rn\right]7s^{2}5d^{10}4f^{14}7p^3{M}^{3+}$
• B. $\left[Rn\right]7s^{2}5d^{10}4f^{14}7p^3{M}^{5+}$
• C. $\left[Rn\right]7s^{2}5d^{10}4f^{14}7p^3{M}^{+}$
• D. $\left[Rn\right]5d^{10}4f^{14}7p^5{M}^{5+}$

Answer 1

Answer: (A)

$\left[Rn\right]7s^{2}5d^{10}4f^{14}7p^3{M}^{3+}$

$115:\left[Rn\right]4f^{14}5d^{10}7s^{2}7p^3$- It has 5 valence electron so it will show $+3$ and $+5$ oxidation state but due to inert pair effect, $+3$ is more stable than $+5$ oxidation state.