Physical and Chemical Changes

Nevaeh’s reactants (baking soda and vinegar) are a total of 55 g. After the reaction, she determined the mass of the products to be 50g. Why has the mass changed?

• A gas formed and left the mixture.

• The vinegar evaporated

• Mixtures are always less massive.

• Some mass was destroyed.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which types of changes observe the Law of Conservation of Mass?

• phase changes

• physical changes

• chemical changes

• physical and chemical changes

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which statement best explains why there is usually less mass at the end of a burning reaction?

• The ash has less volume.

• Some of the matter is destroyed during the reaction.

• The mass of the ash cannot be accurately determined.

• Some of the products of the reaction were given off as a gas.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

One afternoon, Reyshell notices a puddle of water outside in a sunny area. Later, she notices that there is less water than there was earlier. What most likely happened to the water that is no longer on the ground?

• Energy from the Sun destroyed the water.

• Energy from the Sun compressed the volume of the water.

• Energy from the Sun changed the liquid water into water vapor.

• Energy from the Sun transformed the water into another compound.

Tags

NGSS.MS-ESS2-4

NGSS.MS-PS1-4

Which of the following models of a chemical reaction best represents the Law of Conservation of Mass?

• pic 1

• pic 2

• pic 3

• pic 4

Tags

NGSS.MS-PS1-5

Why do water drops form on the lid of a pot of boiling water?

• The lid is hotter than the boiling water, so it turned the steam back into liquid.

• The lid is cooler than the boiling water, so the steam turned back into a liquid.

Tags

NGSS.MS-PS1-4

Measurements during an investigation should be taken at _________.

• the same time and day during each week of the investigation

• different times and days during each week of the investigation

• any time during the first week of the investigation

• one randomly selected time during the investigation

Which is true about physical changes?

• They produce new substances with different properties.

• The materials maintain their original properties.

• They release heat during the changes.

• The changes are irreversible.

What effect does temperature have on how fast a chemical change will occur?

• increasing the temperature causes the change to happen faster

• increasing the temperature causes the change to happen slower

• increasing the temperature has no effect

• increasing the temperature causes the change to stop

Tags

NGSS.MS-PS1-4

Jeffrey gets a glow stick at a party, and he wants to use it the next day. Where should Jeffrey store the glow stick so it will glow the next day?

• freezer

• refrigerator

• outside

• cabinet

Tags

NGSS.MS-PS1-4