Non-metals are all those elements within the periodic table which do not possess the physical and chemical properties of metals.
There are far fewer non-metals than metals, but the range of non-metals is wide, from gases such as Hydrogen and Helium, which are very small atoms, to solids such as Sulphur and Selenium, which are much larger.
There are no non-metals which are liquids at room temperature.
All non-metals are poor, or non-conductors of electricity and, in relation to metals, poor conductors of heat.
The solid non-metals are also too brittle to roll into wires, and are not shiny.