Which natural phenomenon explains why a compass needle always points toward magnetic north?

Which everyday device converts alternating current into direct current for charging electronic devices?

Which common household chemical reaction produces a foaming effect often used in classroom volcano experiments?

Which blood vessels carry oxygenated blood away from the heart to the rest of the body?

Which organ stores bile produced by the liver until it is needed for digestion?

Which gas is responsible for the characteristic smell often associated with rain after a dry spell?