Question

how do the following two elements bond together? k⁺ s²⁻

Explanation:

Step1: Balance ionic charges

Potassium has a +1 charge ($K^+$), sulfur has a -2 charge ($S^{2-}$). We need total positive charge = total negative charge. Let $x$ = number of $K^+$ ions, $y$ = number of $S^{2-}$ ions.
$x(+1) + y(-2) = 0$

Step2: Solve for ion ratio

Substitute to balance: $2(+1) + 1(-2) = 0$. So 2 $K^+$ ions bond with 1 $S^{2-}$ ion.

Answer:

$K_2S$ (the yellow-green bottom option)