Periodic table: number of elements in solid, liquid or gas form at standard sate
However, elements that are gaseous or liquid at room temperature may bond with other elements, and the change in composition can increase interaction between the molecules, lowering the melting or boiling point and causing a change in state. The most obvious example of this is when hydrogen and oxygen molecules bond to form water - it is a liquid at room temperature as the attraction between H2O molecules is much higher than H2 or O2 alone.