Question

what happens to water molecules as water is healed?

a. The molecules become less dense
b. The molecules move more slowly
c. The molecules sink
d. The molecules get closer together
Answer
A cook places a pot of water over a flame on a stove. What will happen to water molecules near the surface of the water?

a. They will become more dense and sink.
b. They will become more dense and rise.
c. They will become less dense and rise.
d. They will become less dense and sink.
Answer
Which option is an example of a transfer of heat by radiation?

a. ice melting in a glass of warm water.
b. a metal spoon in a cup of tea becoming hot.
c. people warming up near a campfire.
d. soup being heated in a bowl in the microwave.
Answer
Which property makes a substance a good conductor of heat?

a. if heat moves through it quickly.
b. if its particles are unlikely to bump together.
c. if its particles are farther apart.
d. if heat is unlikely to escape its surroundings.
Answered by GPT-4o mini
As water is heated, the correct statement is:

a. The molecules become less dense.

When water is heated, the molecules gain energy and move faster, which typically causes them to spread out and become less dense. This is why warm water tends to rise above cooler water.

Options b (The molecules move more slowly) and c (The molecules sink) are incorrect because heating causes molecules to move more quickly, not slowly, and they do not sink. Option d (The molecules get closer together) is also incorrect, as heating generally causes molecules to move apart rather than come closer together.
Answered by GPT-4o mini
The correct answer is:

c. They will become less dense and rise.

As the water near the surface of the pot is heated, the water molecules gain energy and start to move faster. This increased energy causes the molecules to spread out, making the heated water less dense than the cooler water below it. Consequently, the less dense, warmer water rises to the surface.
Answered by GPT-4o mini
The correct answer is:

c. people warming up near a campfire.

Radiation is the transfer of heat through electromagnetic waves, which can occur without direct contact between objects. When people warm up near a campfire, they are absorbing the infrared radiation emitted by the fire, which is an example of heat transfer by radiation.

The other options involve heat transfer by conduction or convection:
- a. Ice melting in a glass of warm water involves conduction.
- b. A metal spoon in a cup of tea becoming hot involves conduction.
- d. Soup being heated in a bowl in the microwave involves both radiation (from the microwave) and conduction (as the soup absorbs heat).
Answered by GPT-4o mini
The correct answer is:

a. if heat moves through it quickly.

A good conductor of heat is characterized by its ability to transfer heat rapidly through its structure. This is typically due to the arrangement and bonding of its particles, which allows them to easily transfer kinetic energy to one another when heated. Materials like metals are good conductors of heat because their particles are arranged in such a way that they can readily transfer heat energy.

The other options do not accurately describe the characteristics of good heat conductors:
- b. If its particles are unlikely to bump together would suggest poor conduction since effective conduction requires particle interactions.
- c. If its particles are farther apart typically refers to gases, which are usually poor conductors of heat.
- d. If heat is unlikely to escape its surroundings relates more to insulation than conduction.