Monay 1

A milliliter of liquid is closest in volume to a:

• large droplet

• capful of liquid

• full glass

• full bucket

Answer explanation

The size of a drop of water varies, but a milliliter is much closer to a single drop than to a larger volume.

Which part of a plant produces most of its food?

• leaves

• roots

• stem

• flowers

Answer explanation

The green part of a plant contains chloroplasts, which have the chlorophyll needed for photosynthesis. While some food is produced in stems, most of it comes from leaves.

Simple machines that use ropes or chains are:

• levers

• wedges

• pulleys

• screws

Answer explanation

Pulleys use a system of ropes or chains. 5th graders are expected to know the types of simple machines and have a basic concept of how they work.

Which of the following is not an observation?

• The clouds are gray.

• It's going to rain soon.

• I hear thunder.

• It is windy.

Answer explanation

Saying it's going to rain soon is making a prediction. It's not a statement of fact. Once the rain starts, you can say it is raining, and that will be an observation.

You set up an experiment to see if soil type affects pea plant growth. The variable you change in the experiment is:

• the pot

• the pea plant

• the soil

• the water

Answer explanation

In an experiment, you try to hold all variables constant (control them), except for one variable, which is called the experimental or independent variable.

The amount of moisture in air is its:

• density

• pressure

• temperature

• humidity

Answer explanation

Humidity is the amount of water vapor in air. Hot air can hold more water than cool air.

If you cool a gas, it may ___ into a liquid:

• condense

• freeze

• evaporate

• melt

Answer explanation

The phase change from a gas to a liquid is called condensation. A familiar example of condensation is when water forms on glass when you come indoors when it's cold outside.

The part of an atom with a negative electrical charge is the:

• electron

• neutron

• atomic nucleus

• proton

Answer explanation

An electron is the part of the atom with a negative charge. Protons carry a positive charge, while neutrons are neutral.

The outer layer of an animal cell is the:

• vacuole

• cell wall

• cytoplasm

• cell membrane

Answer explanation

The outer layer of an animal cell is the cell membrane. Plant cells have a cell wall that encloses the cell membrane.

When magma or lava cools, which type of rock is formed?

• sedimentary

• igneous

• metamorphic

• none of these

Answer explanation

Cooled lava forms igneous rocks.