Our bodies require other elements, including non-metal elements such as phosphorus (P), sulphur (S) and chlorine (Cl), and metal elements like potassium ... one-quarter of the periodic table ...

Mrs Roberts: At its simplest, the periodic table is all the different elements arranged together in a chart. A Russian scientist called Dmitri Mendeleev produced one of the first practical ...

[6 marks] Group 1 of the periodic table contains the alkali metals lithium, sodium and potassium. The alkali metals show a pattern in their reactivity with water. This pattern is shown when small ...