An element is a substance that cannot be broken down into any other substance. There are about 100 elements, each with its own type of . Everything in the universe contains the atoms of at least one or more elements.
The periodic table lists all the known elements, grouping together those with similar . Most elements are metals, which are shiny and conduct electricity well. Metals include gold, aluminium and iron which are all solid at room temperature. Mercury is the only metal that is at room temperature.
Some elements are non-metals. Most non-metals are at room temperature and do not conduct electricity. Non-metal elements with these properties include oxygen, hydrogen and chlorine. A few non-metals, such as carbon and sulphur, are in a state at room temperature.
