Question

1. thinking critically problem solving the metal scandium (sc) has three valence electrons. what is the formula of the ionic compound formed when scandium reacts with iodine?

Explanation:

Step1: Determine scandium ion charge

Scandium has 3 valence electrons, so it loses 3 to form $\text{Sc}^{3+}$.

Step2: Determine iodine ion charge

Iodine (Group 17) gains 1 electron to form $\text{I}^{-}$.

Step3: Balance charges in compound

3 $\text{I}^{-}$ balance 1 $\text{Sc}^{3+}$: $1\times(+3) + 3\times(-1) = 0$.

Step4: Write ionic formula

Combine ions: $\text{ScI}_3$.

Answer:

$\text{ScI}_3$