Final answer:
Elements are classified on the periodic table as metals, nonmetals, or semimetals (metalloids), with metals being conductive and malleable, nonmetals being dull and non-conductive, and semimetals having intermediate properties.
Step-by-step explanation:
Classification of Elements on the Periodic Table
Elements on the periodic table can be classified into three main categories: metals, nonmetals, and semimetals (also known as metalloids). Metals, which occupy the left three-fourths of the periodic table, are typically lustrous, conductive, malleable, and ductile. These elements are shiny and are often silvery in color. Nonmetals, found in the upper right-hand corner of the periodic table (except for hydrogen), are generally dull and poor conductors of heat and electricity. They also tend to be brittle when solid. Semimetals are located along the zigzag line bordering metals and nonmetals and exhibit properties that are intermediate between metals and nonmetals.
Within the metals category, there are further classifications: main-group (representative) elements, transition metals, and inner transition metals. Main-group metals are found in Groups 1A through 8A, transition metals in Groups 3 through 15, and inner transition metals include the lanthanides and actinides, located at the bottom of the periodic table.
Example of Classification
For example, Sodium (Na) is a main-group metal, Iron (Fe) is a transition metal, and Uranium (U) is an inner transition metal. Carbon (C) is a nonmetal, and Silicon (Si) is a semimetal or metalloid.