THE PROPERTIES OF MATERIALS and their （材料和他们的属性）.pdf

THE PROPERTIES OF MATERIALS and their everyday uses Science background for teachers Children need to have experience of, and explore as many different V O C A B U L A R Y materials (substances) as possible in order to make sense of their world. Words to describe Understanding how materials behave in their natural state and under properties: Hard, soft, certain conditions will help them to understand why objects are made strong, weak, tough, of specific materials. Some properties are easily observable features, brittle, stiff, rigid- such as transparency, which they explore as younger children, others flexible, absorbent, are less obvious and need to have tests carried out on them. waterproof, magnetic, In carrying out comparative tests on different materials, children non-magnetic, wear develop an understanding of suitability for different purposes. They and tear, smooth, then begin to develop the skills themselves to choose the best rough, transparent, materials for certain tasks. When testing materials for properties, opaque, translucent precise vocabulary becomes important because children (and adults) Names of a variety of sometimes confuse scientific terms, which they use in a general way in materials: wood, their everyday speech. metals – copper, tin, steel, gold, silver, Hardness Resistance to scratching and pressure. Hardwood does not aluminium, chrome, mark as easily as softwood. plastic – polythene, polystyrene, PVC, Strength Amount of force needed to break a material usually by fabrics – cotton, silk, pushing or pulling down. p