BLUE
What is matter?
Anything that has mass and takes up space.
What are the three common states of matter?
Solid, liquid, and gas.
Which state of matter has a definite shape and definite volume?
Solid.
Which state of matter has a definite volume but takes the shape of its container?
Liquid.
Which state of matter takes both the shape and volume of its container?
Gas.
What happens to ice when it is heated?
It melts and changes from a solid to a liquid.
What is the change from a liquid to a solid called?
Freezing.
What is the change from a liquid to a gas called?
Evaporation or vaporization.
What happens to water when it is placed in a freezer?
It loses thermal energy and freezes into a solid.
What happens to water when it is placed in a freezer?
It loses thermal energy and freezes into a solid.
What happens when water vapor cools and becomes liquid water?
Condensation occurs
What happens to most materials when they are heated?
They gain thermal energy, and their temperature usually increases.
What happens to particles in matter when they are heated?
They generally move faster.
A cold glass of water develops drops of water on its outside. Where did the water come from?
Water vapor in the air cooled and condensed on the glass.
Is melting ice a physical change or a chemical change?
A physical change because the substance remains water.
Is burning wood a physical change or a chemical change?
A chemical change because new substances are produced.
What is the difference between a physical change and a chemical change?
A physical change changes the form or state of a substance, while a chemical change produces one or more new substances.
A student places an ice cube in a cup. After several minutes, the ice cube becomes liquid water. What caused this change?
The ice absorbed thermal energy from its surroundings, causing it to melt.
Why does water evaporate faster on a hot day than on a cold day?
The water particles gain thermal energy and move faster, allowing more particles to escape into the air.
A glass of water is placed in a freezer. What happens to the movement of its particles as the water freezes?
The particles lose thermal energy and move more slowly as the water changes into a solid.
A student observes steam rising from a pot of boiling water. What state of matter is the water in after it changes into water vapor?
Gas.
A substance changes from a gas directly into a solid. What can you conclude about this change?
The substance changed state without becoming a liquid first.
Two identical cups contain equal amounts of water. Cup A is placed in sunlight, and Cup B is placed in a cool room. Which cup will most likely evaporate faster, and why?
Cup A, because the water receives more thermal energy and its particles move faster.
A student says, “When water freezes, it becomes a different substance.” Is the student correct? Explain.
No. Freezing is a physical change. The water changes from a liquid to a solid, but it remains the same substance, H₂O.
A piece of ice melts, the water evaporates, and the water vapor later condenses into liquid water. Are these changes physical or chemical? Explain your answer.
They are all physical changes because the water changes state, but no new substance is formed. The substance remains water throughout the changes.