Phosphorus is a nonmetal. Nonmetals make poor conductors for electricity and heat and have high ionization energies and electronegativities. These elements are listed in the upper right side of the periodic table and include hydrogen, nitrogen, sulfur and selenium.
Metals, such as gold, silver and mercury, are malleable, ductile and typically have high densities and melting points. At room temperature, mercury is a shiny liquid, while most other metals are shiny solids. Metalloids, such as boron, silicon and antimony, have characteristics of both metals and nonmetals. They are brittle semiconductors that don't readily alloy with other metals and lack malleable and ductile properties.