An explosion occurs ...

• Chemical Change

• Physical Change

Answer explanation

An explosion involves a rapid chemical reaction that produces gas and heat, indicating a chemical change. In contrast, physical changes do not alter the substance's chemical structure.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Change in size ...

• Chemical Change

• Physical Change

Answer explanation

A change in size is a characteristic of a physical change, where the substance's form or appearance alters without changing its chemical composition. Therefore, the correct answer is Physical Change.

When something burns it is which of these?

• chemical change
• physical change

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Water turning from a liquid to a solid is a _________________.

• Chemical Change

• Physical Change

• Both

Answer explanation

Water turning from a liquid to a solid is a physical change because it involves a change in state without altering the chemical composition of the water.

Tags

NGSS.MS-PS1-4

Is milk going sour a physical or chemical change?

• Physical 

• Chemical

Answer explanation

Milk going sour is a chemical change because it involves the fermentation process, where bacteria convert lactose into lactic acid, altering the milk's composition and properties.

Tags

NGSS.MS-PS1-2

density

• chemical property

• physical property

Answer explanation

Density is a measure of mass per unit volume and does not involve a chemical change. Therefore, it is classified as a physical property, distinguishing it from chemical properties that involve reactions or changes in composition.

flammability (burns)

• chemical property

• physical property

Answer explanation

Flammability refers to a substance's ability to burn, which is a chemical property. It indicates how a material reacts with fire, distinguishing it from physical properties that do not involve chemical changes.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

luster

• chemical property

• physical property

Answer explanation

Luster refers to the way a surface reflects light, which is a characteristic of the material's appearance. Therefore, it is classified as a physical property, not a chemical property, which involves changes in composition.

a copper penny turning greenish after a few years.

• Chemical Change

• Physical Change

Answer explanation

A copper penny turns greenish due to the formation of copper carbonate and other compounds when it reacts with moisture and air. This process is a chemical change, as it alters the penny's composition.

Tags

NGSS.MS-PS1-2

Melting butter for popcorn

• Physical Change

• Chemical Change

Answer explanation

Melting butter is a physical change because it alters the state from solid to liquid without changing its chemical composition. The butter can solidify again, demonstrating that no new substance is formed.

Tags

NGSS.MS-PS1-4