Sc 8 P 9 2

Derek left the ice cream out on the counter. He noticed that the ice cream began to melt when it was left out at room temperature. What process is Derek observing?

• a physical change

• a chemical change

• a chemical reaction

• the formation of a new substance.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Chemical changes are accompanied by signs that show that a chemical reaction has occurred. By making careful observations about the chemical reaction, a student can see one or more of these signs. The signs will provide evidence that the event is not a physical change. Which of the following is NOT likely to be evidence of a chemical change?

• A form of matter changes state from solid to liquid.

• A substance forms that releases heat and light.

• Carbon dioxide, water, and ash are produced.

• There are signs of rusting on a metal object.

Tags

NGSS.MS-PS1-2

In a physical or chemical reaction, the total amount of the products must be equal to the total amount of the starting materials. Which of the following laws is defined by this statement?

• The Law of Universal Gravitation

• The Law of Chemical Properties

• The Law of Conservation of Energy

• The Law of Conservation of Mass

Tags

NGSS.MS-PS1-5

Two substances, A and Z, are to be identified. Substance A cannot be broken down by a chemical change. Substance Z can be broken down by a chemical change. What can be concluded about these substances?

• Both substances are elements.

• Both substances are compounds.

• Substance A is an element and substance Z is a compound.

• Substance A is a compound and substance Z is an element.

During photosynthesis, the proteins inside chloroplasts in plant cells absorb energy from the Sun. Which statement best describes how photosynthesis follows the law of conservation of energy?

• Electrical energy from the Sun is converted into light energy in plant cells.

• Light energy from the Sun is converted into chemical energy in plant cells.

• Nuclear energy from the Sun is converted into kinetic energy in plant cells.

• Chemical energy from the Sun is converted into thermal energy in plant cells.

Tags

NGSS.HS-LS1-5

Your family is driving to Florida for spring break. As you are moving, the car burns gasoline in the engine. How is energy being transferred in the car’s engine?

• Electrical energy into thermal energy

• Mechanical energy into kinetic energy

• Chemical energy into mechanical energy

• Kinetic energy into potential energy

Tags

NGSS.MS-PS3-4

Matter can go through two types of changes: physical changes and chemical changes. Chemical changes result in new substances, while physical changes do not. Which process is an example of a physical change?

• paper burning into ash

• dough being baked into bread

• apple juice turning into vinegar

• rock being crushed into gravel

David and Roberto made a salt solution by adding 50g of table salt to 100 mL of water. They boiled the solution and noticed that as the water evaporated, some salt crystals formed on the walls of the pot. What can David and Molly infer from this observation?

• Physical changes can be reversed

• Chemical changes can be reversed

• Physical changes cannot be reversed

• Chemical changes cannot be reversed

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

What is the evidence of the chemical change seen here?

• Color change

• Light produced

• state change

• mixture

Tags

NGSS.MS-PS1-2

Which process represents a chemical change?

• A lake freezes over into ice

• Vinegar bubbles when baking soda is added

• A metal bar is rolled into a flat sheet

• Sand, water, and salt combine to form a mixture

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5