Science Sampling Flashcards

What is the function of the heart in the human body?

Answer: To pump blood around the body

The heart is a muscular organ that pumps blood around the body through the circulatory system, delivering oxygen and nutrients to cells and removing waste products.

Which of these changes is reversible?

Answer: Melting chocolate

Melting chocolate is reversible — you can melt it and then cool it to make it solid again. Burning, cooking, and baking cause chemical changes that cannot be undone.

What do producers in a food chain typically get their energy from?

Answer: The Sun

Producers (mainly green plants) get their energy from the Sun through photosynthesis. They convert light energy into chemical energy in their food.

Sound travels fastest through which type of material?

Answer: Solid metal

Sound travels fastest through solids because the particles are closest together, allowing vibrations to pass quickly from one particle to the next. Sound cannot travel through a vacuum at all.

What process do plants use to make their own food?

Answer: Photosynthesis

Photosynthesis is the process by which green plants use sunlight, water and carbon dioxide to make glucose (food) and oxygen.

Which of these is an example of a physical change?

Answer: Dissolving sugar in water

Dissolving sugar in water is a physical change — the sugar can be recovered by evaporating the water. No new substance is formed. Rusting, burning, and cooking are chemical changes.