Compounds
by Kimberly-Dawn R.
Compounds are pure substances that contain two or more elements, combined in a definite fixed proportion. Compounds are made by combining two or more elements. Many words can be made up with just 26 letters of the alphabet; similarly, although there are only about 100 elements, many thousands of compounds may be made by combining them. Here are just a few examples:
Elements
Hydrogen, Oxygen
Carbon, Hydrogen, Oxygen
Carbon, Hydrogen Oxygen
Copper, Sulphur, Oxygen
Sodium, Chlorine
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Compound
Water
Any type of Sugar
any type of Alcohol
Copper(ll) Sulphate
Sodium Chloride (Salt)
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In compounds, atoms of two or more different elements combine in a specific proportion. That is, a certain number of atoms of one element join together in a definite fixed ratio with atoms of another element. Water and Hydrogen Peroxide contain only atoms of hydrogen and oxygen, but the proportions are different. A water molecule never has more nor fewer than two hydrogen atoms combined with one oxygen atom; the atoms are always present in a 2:1 ratio. In a molecule of Hydrogen Peroxide , There are always four atoms, two of hydrogen and two of oxygen.
Pictures of Compounds
Carbon Monoxide
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Carbon Dioxide
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Grade 9 Science Topics Page
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