question:
The ratio of an object's mass to its volume is its
OPTIONS:
- area.
- perimeter.
- density.
- weight.

answer:
density.

question:
Lemon juice turns litmus paper red, is corrosive and tastes sour. Lemon juice is classified as
OPTIONS:
- an acid.
- a base.
- an element.
- More information is needed to classify lemon juice.

answer:
an acid.

question:
What can a moving magnet in a coil of copper wire cause?
OPTIONS:
- an electric current
- friction on wheels
- an increase in gravity
- a decrease in heat

answer:
an electric current

question:
Why should plants be included in investigations about the water cycle?
OPTIONS:
- Plants speed up the water cycle by removing carbon from the air.
- Plants start the water cycle when they make water in photosynthesis.
- Plants are part of the water cycle through the process of transpiration.
- Plants stop the water cycle because they absorb it and stop the flow to streams.

answer:
Plants are part of the water cycle through the process of transpiration.