The periodic table

• an element is a substance made of only one type of atom
• a compound is made of two or more elements chemically bonded
• a mixture is made of 2 or more elements not chemically bonded
• a pure substance consists of only one element or compound
• pure substances have fixed melting and boiling points
• there are 118 elements
• group 1 elements are called alkali metals
• group 2 elements are called alkaline earth metals
• group 7 elements are called halogens
• group 0 elements are called noble gases
• non metals form acidic oxides when they react with oxygen
• lithium burns with a red flame
• sodium burns with a yellow flame
• potassium burns with a lilac flame
• calcium burns with an orange-red flame
• copper (II) burns with a blue-green flame
• nichrome wire it used in flame tests because it is inert, so does not affect flame colour and it has a high melting point