Changes in Matter

1

100

Name a physical change.

evaporation, melting, freezing

200

Toni mixes chocolate powder in her milk. She notices that the chocolate powder dissolves. Based on her observations, what can Toni conclude?

The chocolate powder is a solution.

300

Water can act as a solvent to sugar. What is a solvent?

a substance that is able to dissolve another substance -- the water dissolves the sugar.

400

John makes salad dressing. He puts oil and vinegar in the jar and shakes it. After a few minutes, the oil and the vinegar are separated. What can John conclude about the salad dressing?

The oil and vinegar have formed a mixture.

500

Is salt water a solution or a mixture?

A solution because the salt and the water blend together.

2

100

Petra has four beakers filled with water. In one, she adds red food coloring, she adds sand to the second beaker, ice cubes in the third beaker, and marbles in the last one. She then stirs each beaker. How many of the beakers contain a solution?

Only one beaker contains a solution.

200

Describe what the particles of a solution would look like up close. For example would they be separated from each other or would the particles combine together?

The particles in a solution would be close and connected because they combine together to form a solution.

300

Which chemical property causes iron to become a crumbly, brownish-orange substance over time?

Its ability to rust.

400

Silver can be kept in a box to keep from tarnishing. Suppose one silver spoon is kept in a box, and one silver spoon is left out. Several months later the spoon outside the box is tarnished. What type of change is tarnishing.

Tarnishing is a chemical change.

500

Which of the following is a solution? A. salt water B. sand and water C. muddy water D.

A. salt water

3

100

All matter has certain chemical properties. What is a chemical property?

Any property that describes how substance interacts with other substances.

200

List three chemical changes.

leaves rotting, milk spoiling, food being digested

300

Matter can undergo both chemical and physical changes. Which of the following is a physical change? A. rusting B. tarnishing C. making a solution D. reacting with an acid

C. making a solution

400

When wood burns, a chemical change occurs and smoke and ash form. Describe this change.

New substances form, but the mass of the matter stays the same.

500

Lucia uses a steel wool scrubbing pad to clean a frying pan. If she leaves the wet pad in the kitchen sink for a few days, what will happen?

The steel wool pad will rust.

4

100

Theo and his family take their bikes to the beach. When they return home, Theo notices that the bike chains are rusty, but the frames are not. What can Theo conclude about the materials of the chain and frame?

The frames are made of aluminum and the chains are made of steel.

200

Sometimes our senses tell us when a chemical change has taken place. What is a clue that steel has rusted.

Its color changes.

300

What is a mixture?

a combination of two or more substances that keep their identities

400

What is the best way to prevent steel from rusting?

Keep it dry and sealed in a plastic bag.

500

Katia wants to make iced tea. she adds lemon juice, two spoonfuls of sugar, and crushed ice to some leftover tea. Identify the solvents and solutes.

Solvents: leftover tea. Solutes: lemon juice, sugar, ice

5

100

Katia made tea. Some of the ice in her tea melts. Why?

Heat energy from the leftover tea is transferred to the ice, causing the ice to melt.

200

Compare and contrast a mixture and a solution. Give one example of each.

Both: types of matter that contain more than one substance, keeps its chemical property when combined. Solution: substances are evenly mixed. Mixture: substances are NOT evenly mixed. Fruit salad is a mixture, ocean water is a solution.

300

Is a wood burning fire a chemical change or a physical change?

Chemical change because it cannot be reversed.

400

Identify two physical changes and three chemical changes that take place when a burning candle is blown out and the wax is cooled.

Physical: wax melting, wax hardening. Chemical: the wick burning, the heat and light from the flame, smoke given off by candle.

500

List three chemical reactions that could happen to different materials.

tarnish, bubbles through acid, rust