Complete the exercises below. Identify each of the following elements as a metal, nonmetal, or metalloid: a. phosphorus, b. strontium, c. manganese, d. selenium, e. sodium, f. krypton.

Elements are classified into metals, nonmetals, and metalloids based on their properties and positions in the periodic table. Metals, typically found on the left side, are good conductors of heat and electricity, while nonmetals, located on the right, are poor conductors and often have more varied properties. Metalloids, situated along the zig-zag line, exhibit characteristics of both metals and nonmetals.

Metals are generally characterized by their luster, malleability, ductility, and high electrical and thermal conductivity. They tend to lose electrons during chemical reactions, forming positive ions. Common examples include elements like sodium and strontium, which are essential in various industrial applications and biological processes.

Nonmetals are elements that lack the characteristics of metals and are usually poor conductors of heat and electricity. They can be gases, liquids, or solids at room temperature and often gain electrons in chemical reactions to form negative ions. Elements like phosphorus, selenium, and krypton are examples of nonmetals, each playing crucial roles in biological and chemical systems.