Physical Science

Which of the following provides the best evidence that chemical reaction has taken place?

• Water, when boiled, evaporates and turns to vapor.

• Sugar dissolves completely when added to water.

• A liquid becomes a solid when heat is removed.

• Two liquids are mixed, and a solid substance forms.

In which of the following mixtures is there evidence that a new substance was formed?

• Blue crystals are mixed into a clear liquid, and the volume of the solution increases.

• A clear liquid is mixed with a yellow liquid, and heat energy is released.

• A salt water solution is boiled, and salt crystals a can be seen on the bottom of the container.

• A clear liquid is mixed with a yellow powder, and the powder dissolves completely.

Which of the following observations support the conclusion that a new substance was formed?

• Most of the solid dissolved into the liquid.

• The temperature of the solution decreased.

• The volume of the substance increased.

• Some of the substance remained at the bottom.

A chemical reaction is indicated in all of the following situations EXCEPT...

• gas bubbles form when baking soda is added to vinegar.

• a clear liquid becomes a solid when heat energy is removed.

• the temperature of a solution decreases when a powder is added.

• a yellow solid forms when two clear liquids are mixed together.

No matter what type of change matter goes through, chemical or physical, every time matter alters its form...

• the matter releases heat energy.

• some of the matter is destroyed.

• new matter will be created.

• the amount of matter is the same.

A student placed a beaker of water near a window in the classroom and recorded the volume of water in the beaker for three weeks.

Week 1: 100 mL

Week 3: 22 mL

What volume of liquid was converted to water vapor that entered the air over the three week period?

• 22 mL

• 78 mL

• 100 mL

• 122 mL

A student places 100 grams of water and 50 grams of ice into a beaker. Which of the following is the best prediction for the mass of the contents of beaker after the ice has melted into water?

• 25 grams

• 50 grams

• 100 grams

• 150 grams

A dish has a mass of 72 grams. Then 12 grams of butter is placed on the dish, and the butter melts. Which of the following best describes the mass of the dish and the butter before and after melting?

• before: 84 g

  after: 72 g

• before: 84 g

  after: 87 g

• before: 84 g

  after: 84 g

• before: 72 g

  after: 12 g

Which of the following would provide the best evidence that air is made of matter?

• Making a small hole in a tire and measuring the amount of time it takes for it to become flat.

• Comparing the volume of an empty balloon to the volume of an inflated balloon.

• Measuring the temperature of the air in several rooms of varying sizes.

• Finding the volume of the air between marbles in a jar by pouring water over them.

Which of the following is always true about particles that make up matter?

• They can only be found in solid substances.

• They are too small to be seen with only our eyes.

• They are the same size in all substances.

• They are locked into regular arrangements.