Question

question 36
1 pts
give the ground state electron configuration for mg²⁺.
1s²2s²2p⁶3s²
1s²2s²2p⁶3s²3p²
1s²2s²2p⁶
1s²2s²2p⁶3s²3p⁶
1s²2s²2p⁶3s¹

question 37
1 pts
give the ground state electron configuration for se²⁻.
ar4s²3d¹⁰4p⁴
ar4s²3d¹⁰4p⁶
ar4s²3d¹⁰4p²
ar4s²4p⁶
ar4s²3d⁸4p⁶

Explanation:

Step1: Determine Mg's atomic number

Magnesium (Mg) has an atomic number of 12, so neutral Mg has 12 electrons.

Step2: Consider the ion charge

$Mg^{2 +}$ has lost 2 electrons. So it has 12 - 2=10 electrons.

Step3: Write the electron - configuration

The electron - configuration for 10 electrons is $1s^{2}2s^{2}2p^{6}$.

Step1: Determine Se's atomic number

Selenium (Se) has an atomic number of 34, so neutral Se has 34 electrons.

Step2: Consider the ion charge

$Se^{2 -}$ has gained 2 electrons. So it has 34+2 = 36 electrons.

Step3: Write the electron - configuration

The noble - gas core for 36 electrons is [Ar], and the remaining electron - configuration is $4s^{2}3d^{10}4p^{6}$.

Answer:

$1s^{2}2s^{2}2p^{6}$