Question

1. the table shows the mass of different substances before and after a physical change.

substance before change after change
ice pop 80 g 80 g
candle wax 60 g 60 g
frozen juice 120 g 120 g
what conclusion can you draw?
a. melting makes objects lose mass.
b. mass is conserved even when substances change state.
c. liquids always weigh more than solids.
d. the frozen form always weighs less.

1. which of the following are examples of conservation of matter? (select all that apply.)

a. water boiling in a sealed pot, mass stays the same.
b. burning wood outside and only measuring the ashes.
c. dew forming on grass in the morning.
d. an ice cube melting in a closed container.
e measuring a soda can before and after freezing in a sealed container.

1. a sponge filled with water is placed in a sealed box on a scale. hours later, the sponge is dry, but the box still weighs the same.

what does this show?
a. the water evaporated and stayed inside the box as gas.
b. the mass was lost because evaporation destroys matter.
c. the sponge lost weight, so the system has less mass.
d. the gas disappeared when the sponge dried.

Explanation:

Step1: Analyze question 5

The table shows mass before and after physical - state changes (melting for ice pop and frozen juice, change in wax state) and mass remains the same.

Step2: Evaluate option A

Melting does not make objects lose mass as shown in the table, so A is incorrect.

Step3: Evaluate option B

The data in the table shows that mass is conserved during state - changes, so B is correct.

Step4: Evaluate option C

The table does not compare weights of liquids and solids in general, so C is incorrect.

Step5: Evaluate option D

The table shows no indication that frozen form weighs less, so D is incorrect.

Step6: Analyze question 6

Conservation of matter means mass remains the same in a closed system during physical or chemical changes.

Step7: Evaluate option A

In a sealed pot, water boiling is a physical change and mass stays the same, so A is an example of conservation of matter.

Step8: Evaluate option B

Burning wood is a chemical change. Measuring only ashes does not account for gases released, so it is not a good example of conservation of matter.

Step9: Evaluate option C

Dew formation is a physical change of water vapor condensing. In a natural environment, it is part of a larger system where mass is conserved, but it is not a closed - system example as clearly as others.

Step10: Evaluate option D

An ice cube melting in a closed container is a physical change with mass conservation, so D is an example.

Step11: Evaluate option E

Freezing a soda can in a sealed container is a physical change and mass is conserved, so E is an example.

Step12: Analyze question 7

A sponge with water in a sealed box has the same mass when the sponge is dry.

Step13: Evaluate option A

The water evaporated and stayed in the box as gas, keeping the total mass the same, so A is correct.

Step14: Evaluate option B

Evaporation does not destroy matter, so B is incorrect.

Step15: Evaluate option C

The system's mass did not change, so C is incorrect.

Step16: Evaluate option D

The gas did not disappear, so D is incorrect.

Answer:

1. B. Mass is conserved even when substances change state.
2. A. Water boiling in a sealed pot, mass stays the same; D. An ice cube melting in a closed container; E. Measuring a soda can before and after freezing in a sealed container.
3. A. The water evaporated and stayed inside the box as gas.