Memory Game MATTER AND ENERGY, CALP, YEAR 1Online version Listen, read and match. by Rafael Rodríguez Pérez Some materials change their state. Materials can be rough, smooth, soft, hard, rigid, flexible, transparent or opaque. Energy can be produced from renewable sources. Mixtures are made of more than 1 thing. Materials can be natural or manufactured. Energy can be produced from non-renewable sources. Pure substances are made of 1 thing.