To determine the correct formula for the compound formed between potassium (K) and sulfur (S), we need to consider the valencies (or oxidation states) of the two elements:
1. Potassium (K) has a valency of [tex]\( +1 \)[/tex]. This means each potassium atom wants to lose one electron.
2. Sulfur (S) has a valency of [tex]\( -2 \)[/tex]. This means each sulfur atom wants to gain two electrons.
To balance the charges between potassium and sulfur atoms in a neutral compound, we need to ensure the total positive charge from the potassium atoms equals the total negative charge from the sulfur atoms.
- Since each potassium atom contributes a [tex]\( +1 \)[/tex] charge, we would need two potassium atoms to balance the [tex]\( -2 \)[/tex] charge from one sulfur atom.
- Therefore, the chemical formula requires two potassium (K) atoms for each sulfur (S) atom.
So, the correct formula is [tex]\( K_2S \)[/tex].
The correct choice among the given options is:
[tex]\[ \boxed{K_2S} \][/tex]
