Density Checkin

What happens to a hot water balloon when placed in cold water?

• It sinks to the bottom

• It floats to the top

• It remains at the same level

• It bursts

Answer explanation

When a hot water balloon is placed in cold water, it floats to the top due to the temperature difference causing the air inside to cool and contract, making it less dense than the surrounding water.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Why does a hot water balloon float in cold water?

• The hot water balloon has more particles per unit of volume.

• The hot water balloon is less dense than the cold water.

• The hot water balloon is more dense than the cold water.

• The cold water freezes the hot water balloon.

Answer explanation

The hot water balloon is less dense than the cold water

What is the principle behind less dense substances floating in more dense substances?

• Gravitational pull is weaker on less dense substances

• Less dense substances have fewer particles per unit of volume

• More dense substances always dissolve less dense substances

• Less dense substances are always hotter

Answer explanation

Less dense substances float in more dense substances because they have fewer particles per unit of volume.

What would likely happen to a hot water balloon inside a beaker of oil?

• It will float to the top

• It will sink to the bottom

• It will dissolve in the oil

• It will expand and burst

Answer explanation

The hot water balloon is less dense than the oil, causing it to float to the top due to buoyancy.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Using the particle model, why does a cold-water balloon sink in hot water?

• The cold-water balloon has fewer particles per unit of volume

• The cold-water balloon has more particles per unit of volume

• The hot water is less dense than the cold-water balloon

• The hot water freezes the cold-water balloon

Answer explanation

The cold-water balloon has more particles per unit of volume

Tags

NGSS.MS-PS1-4

Which square has more particles, A or B?

• Square A

• Square B

• Both have the same number of particles

• Cannot be determined from the image

Answer explanation

Square B has more particles than Square A, as indicated in the question. Therefore, the correct choice is Square B.

Which square has a greater density, A or B?

• Square A

• Square B

• Both have the same density

• Cannot be determined from the image

Answer explanation

Square B has a greater density as it has more dots packed into the same area compared to Square A.

Do squares C and D have the same number of particles?

• Yes, they have the same number of particles.

• No, square C has more particles.

• No, square D has more particles.

• The number of particles cannot be determined from the information provided.

Answer explanation

Yes, they have the same number of particles.

Which square has a greater density?

• Square C has a greater density.

• Square D has a greater density.

• Both squares have the same density.

• The density cannot be determined from the information provided.

Answer explanation

Square D has a greater density because it has more dots in a smaller area compared to Square C.

Why might square D have a greater density than square C?

• Because it has more particles in the same amount of space.

• Because it has fewer particles in the same amount of space.

• Because it has the same number of particles in a smaller space.

• Because it has the same number of particles in a larger space.

Answer explanation

Because it has the same number of particles in a smaller space.