The group of elements to the right of the heavy, stepped, diagonal line in the periodic table.

the elements in the upper right part of the periodic table, and also hydrogen.

Elements that have a dull appearance; are not malleable; are poor conductors of heat and electricity; and tend to gain electrons to form negative ions. They are thus opposite of metals in most regards, as befits their name. In addition to hydrogen, in Group 1 of the periodic table, the other 18 nonmetals occupy the upper right-hand side of the chart. They include the noble gases, halogens, and seven "orphan" elements: boron, carbon, nitrogen, oxygen, phosphorus, sulfur, and selenium.