Nemfém

Nemfém, or nonmetal, is a chemical element that lacks the characteristic properties of metals. Nonmetals occupy the right side of the periodic table (primarily the p-block) and include hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, the halogens, and the noble gases. Some elements—such as boron and silicon—are on the border between metal and nonmetal and are often classified as metalloids.

Physically, nonmetals vary widely. Many are gases at room temperature (hydrogen, nitrogen, oxygen, the noble gases) or a liquid (bromine), while others are solids (carbon, phosphorus, sulfur). They are generally poor conductors of heat and electricity and tend to be brittle when solid, in contrast to metals’ malleability and luster. Chemically, nonmetals tend to form covalent bonds and tend to gain or share electrons rather than lose them, often producing acidic or neutral oxides. They can form a wide range of compounds, from simple diatomic molecules like O2 and N2 to complex organic molecules essential for life.

Nonmetals play a central role in biology and the environment. Oxygen, carbon, nitrogen, phosphorus, and sulfur are key elements in biomolecules; halogens participate in diverse reactions, and noble gases serve in inert atmospheres and lighting. Industry uses nonmetals in fuels, fertilizers, plastics, pharmaceuticals, and electronics. The term also encompasses variable properties across the group, with exceptions and overlaps near metalloid boundaries.