How microwaves work

What phenomenon did Percy Spencer observe that led to the invention of the microwave oven?

• A candy bar melted in his pocket

• A radio signal was interrupted

• A light bulb glowed brighter

• A metal object sparked

How do microwaves heat food?

• By altering chemical bonds

• By creating frictional heat

• By ionizing radiation

• By direct conduction

Why do microwaves interact strongly with water molecules in food?

• Because water molecules are non-polar

• Because water molecules are polar

• Because water molecules are metallic

• Because water molecules are inert

What does microwave radiation in physics describe?

• Sound waves

• A type of light visible to humans

• Transfer of energy across a gap

• A dangerous form of energy

Why is microwaving metal sometimes dangerous?

• It makes the food toxic

• It can cause sparks

• It has no effect

• It stops the microwave