Matter is anything that takes up space and has mass or weight. Matter exists in three forms or states - solid, liquid and gas. All matter is made up of molecules, the smallest part of a substance that can still be that substance. Molecules in gases are far apart and they move around more. Gases have no definite size or shape. Liquids molecules are closer together than those of gases but less so than those of solids. Liquids have a definite size or volume but liquids take the shape of the container they are in. The molecules in solids are close together and do not move about as much as those of gases and liquids. Solids have a definite shape and size or volume. States of matter change according to the amount of heat applied to them or taken from them. Solids change to liquids with more heat added. The changing of a solid to a liquid is called melting. Liquids molecules move freely about each other, but are held together by adhesion and cohesion. When liquids are heated, these forces of adhesion (molecules of two different substances cling to one another) and cohesion (it s molecules of the same substance cling together) are broken and the liquid becomes a vapor or gas. Matter has certain properties or characteristics that make them different from each other. Metals have different degrees of ductility which is the ability of a metal to plastically deform without breaking or fracturing, with the cohesion between the molecules remaining sufficient to hold them together. Elasticity is the ability of a body to resist a distorting influence or stress and to return to its original size and shape when the stress is removed. For example, a rubber band has a higher degree of elasticity than a wooden plank - it can be twisted and turned and still return to its original shape without breaking. Malleability is the property of a metal describing the ease with which it can be hammered, forged, pressed, or rolled into thin sheets. Porosity is ability to permit another substance to flow through it. Paper towels would allow liquids to be soaked into them and thus have a good degree of porosity. Tenacity is the resistance to being pulled apart.
Posted on: Mon, 19 Jan 2015 07:24:22 +0000
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