convection

When air is heated, its density ___________.

• increases

• decreases

• remains the same

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

The diagram shows a refrigerator. The cooling unit is placed at the top. The cooling unit cools the air near it. What happens to the density of the air as it cools, and how does it move?

• The density of air increases. It moves down.

• The density of air increases. It moves up.

• The density of air decreases. It moves down.

• The density of air increases. It moves up.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

The diagram shows some rice being boiled in a pan. What is the main methods by which thermal energy is transferred (i) through the metal pan and

(ii) through the water?

• (i) conduction (ii) conduction

• (i) convection (ii) convection

• (i) conduction (ii) convection

• (i) convection (ii) conduction

Tags

NGSS.MS-PS3-4

Convection can take place in ____________.

• solids only.

• liquids only.

• liguids and gases only.

• solids, liquids and gases.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

In the process of convection, energy is transferred _________.

• because of temperature differences in a solid

• because of density differences in a liquid

• by the diffusion of molecules throughout a fluid

• by the vibration of molecules

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

In an ocean, warm water moves __________ and cold water moves ____________.

• Down, Up
• Up, Down

Tags

NGSS.MS-ESS2-6