What is the capital gains tax? A. Tax that is paid to people who are self-employed B. Tax that is used to provide income for retired and disabled people and their families C. Tax that applies to investments and other personal property D. Tax that is used to provide medical benefits for people age 65 and older

Balanced chemical reaction: 2K + S → K₂S, product of reaction is potassium sulfide.
There are same number of atoms on both side of chemical reaction, two potassium atoms and one sulfur atom.
Potassium oxidizes from zero to +1 oxidation number and sulfur is reduced from zero to -2 (gain two electrons).