The document describes several chemistry experiments involving chemical and physical changes. Examples of chemical changes included reactions between magnesium and oxygen, magnesium and hydrochloric acid, electricity and hydrochloric acid, cobalt chloride and calcium hydroxide, potassium permanganate and sodium sulphite. Examples of physical changes involved processes like a collapsing can, dissolved tea powder, a vacuum pump and marshmallow, wax changing state from solid to liquid, and ice cubes melting.