tailieunhanh - English for students of Physics_Unit 3

Chemical reactions occur continuously in the atmosphere, in factories, in vehicles, in the environment, and in our bodies. In a chemical reaction, one or more kinds of matter is changed into a new kind-or several new kinds-of matter. A few common chemical reactions are shown here. Life as we know it could not exist without these processes: plants could not photosynthesize, cars could not move, pudding could not thicken, muscles could not burn energy, glue could not stick, and fire could not burn. . | 35 Chemical reactions occur continuously in the atmosphere in factories in vehicles in the environment and in our bodies. In a chemical reaction one or more kinds of matter is changed into a new kind-or several new kinds-of matter. A few common chemical reactions are shown here. Life as we know it could not exist without these processes plants could not photosynthesize cars could not move pudding could not thicken muscles could not burn energy glue could not stick and fire could not burn. Unit Three MATTER AND MEASUREMENT 36 READING PASSAGE Matter and Measurement Matter in science is the general term applied to anything that has the property of occupying space and the attributes of gravity and inertia. In classical physics matter and energy were considered two separate concepts that lay at the root of all physical phenomena. Modern physicists however have shown that it is possible to transform matter into energy and energy into matter and have thus broken down the classical distinction between the two concepts. When dealing with a large number of phenomena however such as motion the behavior of liquids and gases and heat scientists find it simpler and more convenient to continue treating matter and energy as separate entities. Certain elementary particles of matter combine to form atoms in turn atoms combine to form molecules. The properties of individual molecules and their distribution and arrangement give to matter in all its forms various qualities such as mass hardness viscosity fluidity color taste electrical resistivity and heat conductivity among others. In philosophy matter has been generally regarded as the raw material of the physical world although certain philosophers of the school of idealism such as the Irish philosopher George Berkeley denied that matter exists independent of the mind. Matter exists in three states solid liquid and gas. A solid for example a stone has a definite shape and a definite volume a liquid for example oil has definite .