Understanding Check 1: Ions and Conductivity

Why does salt solution conduct electricity better than distilled water?

• It contains more oxygen molecules

• It has free-moving ions that carry charge

• It has fewer water molecules

• It reflects more light

What particles are responsible for carrying electric current in metals?

• Ions

• Protons

• Electrons

• Neutrons

When salt (NaCl) dissolves in water, what happens to its particles?

• They melt into liquid sodium

• They form neutral water molecules

• They split into positively and negatively charged ions

• They disappear completely

Which of the following would be the BEST conductor?

• Distilled water

• Plastic

• Copper tape

• Sugar water

What can scientists learn by measuring the conductivity of river water?

• The color of the water

• The amount of dissolved salts or pollutants

• The temperature of the river

• The speed of water flow