What are the cations and anions of K2S?

Question

I know that this is soluble. I also know that k is + and s-2.

How do I name anions and cations?

Answer 1

K+ is potassium ion, and S2- is sulphide ion.

Since potassium takes only one valency, its ion can simply be mentioned as potassium ion or potassium cation.

Other cations (of electropositive metals) are also named similarly e.g. Na+ sodium ion; Mg2+ magnesium ion; H+ hydronium ion / hydrogen ion; Al3+ aluminium ion, etc

All electronegative ions i.e. anions are named by suffixing "-ide" e.g.S2- sulphide; O2- oxide; F- fluoride; Cl- chloride; N3- nitride, H- hydride etc

The compound K2S is called potassium sulphide.