Question

question 4 of 15
which of the following are good conductors under normal conditions?
check all that apply.
a. plastic
b. air
c. water
d. ceramic
e. gold
f. a penny

Explanation:

• Gold (E): Metals are generally good conductors of electricity. Gold is a metal and has free electrons that can move easily, allowing it to conduct electricity well.
• A penny (F): Pennies are made of metal (copper - zinc alloy). Metals have a sea of delocalized electrons which enables them to conduct electricity.
• Water (C): Pure water is a poor conductor, but normal water (tap water) contains dissolved salts (ions). Ions in solution can move and carry an electric charge, making it a conductor.
• Plastic (A): Plastics are polymers. They have covalent bonds and no free - moving charged particles (electrons or ions in significant amounts) under normal conditions, so they are insulators.
• Air (B): Air is a mixture of gases. Gases under normal conditions have very few free - moving charged particles (except in ionized state like in lightning, but that's not normal conditions). So air is an insulator.
• Ceramic (D): Ceramics are made of non - metallic minerals. They have ionic and covalent bonds. In their normal state, they lack free - moving charged particles (electrons or ions) to conduct electricity, so they are insulators.

Answer:

C. water, E. gold, F. a penny