Question

two species with the same electron configuration are said to be isoelectronic. a given electron configuration is 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶. which of the following isoelectronic atoms or ions match this electron configuration? choose 3 answers: a k⁺ b as³⁺ c zn²⁺ d as³⁻ e kr f rb⁺

Explanation:

Step1: Calculate number of electrons in given configuration

The sum of electrons in $1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{6}$ is $2 + 2+6 + 2+6+2 + 10+6=36$.

Step2: Analyze each option

• For $K^{+}$: Potassium (K) has 19 electrons. $K^{+}$ has $19 - 1=18$ electrons.
• For $As^{3 +}$: Arsenic (As) has 33 electrons. $As^{3+}$ has $33-3 = 30$ electrons.
• For $Zn^{2+}$: Zinc (Zn) has 30 electrons. $Zn^{2+}$ has $30 - 2=28$ electrons.
• For $As^{3-}$: Arsenic (As) has 33 electrons. $As^{3 -}$ has $33+3=36$ electrons.
• For $Kr$: Krypton (Kr) is a noble - gas with 36 electrons.
• For $Rb^{+}$: Rubidium (Rb) has 37 electrons. $Rb^{+}$ has $37 - 1=36$ electrons.

Answer:

D. $As^{3-}$
E. $Kr$
F. $Rb^{+}$