Question

how are compounds formed?
condensation
evaporation
percolation
chemical change

Explanation:

Compounds are formed through chemical changes where atoms of different elements combine chemically to create substances with new properties. Condensation is a change of state from gas to liquid, evaporation is from liquid to gas, and percolation is the movement of fluids through porous materials. None of these directly form compounds like a chemical change does.

Answer:

chemical change