Fundamental ideas

protons and electrons make up a nucleus, this being surrounded by electrons makes up an atom- tiny particles are called atoms. protons have a positive charge, neutrons have a neutral charge and electrons have a negative charge. the atomic number is the amount of protons the atom contains. whereas mass number is the total number of protons and neutrons.

when an element from group 1 reacts (vigorously) with water it forms metal hydroxides (strong alkalis) and hydrogen. left side of periodic table = alkali metals which form alkaline compounds, group o = noble gases.

elements react to form compounds

• ionic bonds are created by metals & non-metals, consisting of ions
  > metal atoms lose electrons to form positively charged ions
  > non-metal atoms gain electrons to from negatively charged ions

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