Write the names and symbols for four elements in each of the following categories: (a) nonmetal, (b) metal, (c) metalloid.

Nonmetals are elements that tend to be poor conductors of heat and electricity, and they are not lustrous. They are found primarily on the right side of the periodic table. Unlike metals, nonmetals can be gasses, liquids, or solids at room temperature. Their physical properties vary widely, but they often have a non-metallic luster and display a wide range of colors and shapes. In the periodic table example, we identified Hydrogen (H), Carbon (C), Oxygen (O), and Nitrogen (N) as nonmetals.

Each of these nonmetals is unique. Hydrogen, primarily known as a gas, is abundant in the universe and is a part of water. Carbon is the foundation of organic chemistry and is present in all known life forms. Oxygen is essential for respiration for many organisms, and Nitrogen makes up a significant part of the Earth's atmosphere. Nonmetals play critical roles in the chemistry of life, forming the basis of the compounds that make up organisms and their environments.

Metals are typically shiny, malleable, and good conductors of electricity and heat. They are mostly located on the left side and in the center of the periodic table. Metals are known for their ability to bend without breaking and are usually solid at room temperature, except for mercury, which is a liquid. The provided examples from the exercise—Lithium (Li), Beryllium (Be), Aluminium (Al), and Iron (Fe)—are all metals with unique properties and uses.

Lithium is the lightest metal and used in batteries; Beryllium has a high melting point and is used in aerospace materials; Aluminum is known for its low density and high corrosion resistance, making it perfect for foil and cans; while Iron is the most used metal on earth, central to construction and manufacturing, thanks to its strength and abundance. Metals form a significant part of modern civilization, being used in everything from infrastructure to technology.

Metalloids possess a mix of properties that make them sit between metals and nonmetals on the periodic table, often found along the staircase line. These elements can conduct electricity better than nonmetals but not as well as metals, which makes them valuable as semiconductors. In the exercise, we saw examples such as Boron (B), Silicon (Si), Germanium (Ge), and Arsenic (As).

Boron is used in borosilicate glass and as a semiconductor dopant. Silicon is the most famous metalloid, being crucial to electronic devices as the primary material in microchips. Germanium also finds use in electronics and fiber optics due to its transparent qualities. Arsenic has a historical significance in pesticides, although it's less commonly used today due to toxicity. Metalloids have a significant impact on technology and various industries, chiefly due to their semiconductor capabilities.