Materials
Name one natural material.
Wood, wool, stone, sand, or cotton.
What are the three states of matter?
Solid, liquid, and gas.
You put a tray of water in the freezer. The next morning, it is ice. What change happened?
Freezing.
What gives water the energy it needs to evaporate?
The Sun.
An ice cube melts into water. Is this change reversible or permanent?
Reversible. The water can freeze again.
Name one processed material.
Paper, glass, or plastic.
Which state keeps its own shape?
A solid
An ice cube is left on the kitchen counter and becomes a small puddle. What change happened?
Melting.
Rainwater gathers in lakes, rivers, and oceans. What part of the water cycle is this?
Collection.
A log burns and turns into ash. Is this change reversible or permanent?
Permanent. The ash cannot become the original log again.
Which is natural and which is processed: wood and paper?
Wood is natural. Paper is processed.
Which state flows and takes the shape of its container?
A liquid flows and takes the shape of its container.
After a rainy day, a puddle gets smaller even though no one splashed it away. Where did the water go?
Evaporation.
The Sun warms lake water, and some changes into water vapour. What part of the water cycle is this?
Evaporation.
You stretch an elastic band and let go. Why is this change reversible?
It returns to its original shape
What is the difference between natural and processed materials?
Natural materials come from nature. People change materials to make processed materials.
What happens to a gas when it goes into a container?
It spreads out to fill the container.
After a warm shower, tiny water drops cover the bathroom mirror. What change caused the drops to form?
Condensation. Water vapour cooled and changed into liquid drops.
Water vapour cools and forms tiny water drops that make clouds. What part of the water cycle is this?
Condensation.
You bake cake batter into a cake. Why is this change permanent?
The cake cannot be changed back into the original batter.
A student says, “Plastic is natural because oil comes from the Earth.” Is the student correct? Explain.
No. Plastic is processed because people change the oil to make a new material. A processed material can start with something from nature.
How are the particles in a solid different from the particles in a gas?
Solid particles are close together. Gas particles are far apart.
You want to turn an ice cube into water vapour. What two changes must happen?
Melting, then evaporation. The ice becomes liquid water, then the liquid water becomes a gas.
Water falls from clouds as rain, snow, sleet, or hail. What part of the water cycle is this?
Precipitation.
A student says, “Every change caused by heating is permanent.” Explain why this is incorrect.
Some changes caused by heating are reversible. For example, melted chocolate can cool and become solid again.