Chemistry
ATOMIC STRUCTURE AND THE PERIODIC TABLE ideas you HaVe met Before:
eLements, mixtures and ComPounds • Mixtures can be separated easily by fi ltering and other ways. • Elements cannot be broken down by chemical means. • Compounds are made from elements chemically combined.
atoms and tHeir struCture • Electrons have a negative charge. • Atoms have a nucleus with a positive charge. • Electrons orbit the nucleus in shells.
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some eLements and tHeir ComPounds • Helium is unreactive and used in balloons. • Sodium chloride is used to fl avour and preserve food. • Chlorine is used to kill bacteria in swimming pools.
metaLs in tHe PeriodiC taBLe • Gold, silver and platinum are precious metals. • Mercury is a liquid metal. • Zinc, copper and iron are used to make many useful objects.
metaLs and non-metaLs • Gold, iron, copper and lead are metals known for centuries. • Oxygen and nitrogen are gases of the air. • Sulfur is a yellow non-metal.
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AQA GCSE Chemistry: Student Book
16788_P012_055.indd 12
2/11/17 11:56 AM