Question

part 1 (0.3 point)
se has valence electrons.

part 2 (0.3 point)
se²⁻ has valence electrons.

part 3 (0.3 point)
cs⁺ has valence electrons.

part 4 (0.3 point)
i⁻ has valence electrons.

Explanation:

Part 1 Step1: Find Se's group

Se is in Group 16.

Part 1 Step2: Determine valence electrons

Group 16 elements have 6 valence electrons.

Part 2 Step1: Se gains 2 electrons

Se²⁻ = Se + 2 electrons.

Part 2 Step2: Calculate valence electrons

6 + 2 = 8.

Part 3 Step1: Cs's group and ion formation

Cs is Group 1; Cs⁺ loses 1 electron.

Part 3 Step2: Find valence electrons of Cs⁺

Cs⁺ has the electron configuration of Xe, with 8 valence electrons.

Part 4 Step1: I⁻ formation

I gains 1 electron to form I⁻.

Part 4 Step2: Calculate valence electrons

I (Group 17, 7 valence e⁻) +1 = 8.

Answer:

6
8
8
8