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