Non-metals are found in the p−block of the modern periodic table.
In periodic table group 13 to 18 contain most of the non-metals.
In their outermost shell, non-metals usually have 4, 5, 6, or 7 electrons.
Non-metals are those that lack any of the metallic characteristics.
Most of them are gas and often liquid.
Non-metal does not react with water, but in air, it is typically very reactive, so some of them are preserved in water.
For example, Phosphorus is one of the most reactive non-metals and it catches fire when exposed to sunlight, which is why it is contained in water to avoid its interaction with oxygen in the atmosphere.