A compound is a substance that is formed when two or more different chemical elements bond together in a fixed ratio, like water (H₂O) from hydrogen and oxygen or salt (NaCl) from sodium and chlorine.

Did you know that alum is commonly known as 'fitkari'? Alum is a class of hydrated double sulphate salts. Alum is referred to as a double salt because it contains two different cations (like K⁺ and ...