Physical Science Flashcards

Which of the following best describes the law of conservation of mass?

Answer: In a chemical reaction, the total mass of reactants equals the total mass of products

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction.

A student observes that iron rusts when exposed to oxygen and water. This is best classified as a:

Answer: Chemical change

Rusting is a chemical change because a new substance (iron oxide) is formed with different properties from the original iron.

Which of Newton's laws of motion states that for every action there is an equal and opposite reaction?

Answer: Third law

Newton's Third Law states that forces always come in equal and opposite pairs between interacting objects.

What type of energy is stored in the chemical bonds of food?

Answer: Chemical potential energy

Food stores chemical potential energy in molecular bonds, which is released during cellular respiration.

Which best explains why metals are good conductors of electricity?

Answer: Metals have free electrons that can move easily through the material

Metals have a 'sea of electrons' that are not bound to individual atoms, allowing electric charge to flow freely.

A teacher demonstrates that sound cannot travel through a vacuum by placing a ringing alarm inside a sealed jar and pumping out the air. What concept does this illustrate?

Answer: Sound requires a medium to travel through

Sound is a mechanical wave that requires a medium (solid, liquid, or gas) to propagate; it cannot travel through empty space.