Change of atomic radius:
As you go down the nonmetals elements the atomic radios increases by one electron shell. The element’s atomic radius from left to right increases, it gains one electron on the outermost shell.
Location On Period Table:
Nonmetals are in the last columns of the period table because the element’s outer shell has 4 to 8 electrons, the reason being for having those elements on groups 13 to 18 on the periodic table.
Nonmetals are reactive, the nonmetals elements that are further way from the 8th group of the period table are the most reactive elements. The reason being is that elements that have less electrons on the outermost shell are most likely to have bonds, in some causes the elements have to lose or gain electrons to bond.
Nonmetals can be used for different purposes, for example oxygen is used for breathing, phosphorus is used to produce crackers, chloride is used to clean and purify water, nitrogen and potassium are used in fertilisers, graphite is used to conduct electricity and to produce lead, and etc…
Boiling and Melting point:
Most non-metals have low melting and boiling points, for example phosphorus, sulphur, and iodine have melting points of 44, 115 and 114 degrees Celsius and the boiling points of 280, 445, and 184 degrees Celsius . Even though carbon, silicon and boron have a very high melting and boiling points. Nonmetals have a very low density, because most of the elements are gases and liquids. Therefore the nonmetal elements will melt and boil faster.
Nonmetals are found naturally in the atmosphere, therefore they are not manmade elements. Some of the sulphur is accumulated about 1,000 feet beneath the Earth surface. Nonmetals can be mixed into different elements, for example in some cases sulfur is mixed with rocks.