Classification of Elements ... one type of compound is transformed into another type of compound, the chemical reaction is then called oxydation and reduction. // the polar- numher is increased ...

Many chemical reactions are irreversible ... Investigate some changes at home or in school (with a grown up to help) and classify them as reversible or irreversible. You could try: stirring ...

Some chemical reactions change temperature, change color, produce a gas, or make a solid from two liquids. Try this reaction and see what it does! Pour 1 tablespoon of hydrogen peroxide into a cup.