1.3 Using the particle model

Dry ice can keep vaccines ....................................................

• colder than -70 °C.

• warmer than 70 °C.

• at 70 °C.

• warmer than -70 °C.

Why does dry ice in the gas state spread out and take the shape of its container?

• The particles are far apart

• The particles move around

• The particles are arranged in fixed positions

• The particles hold together strongly

Different parts of the particle model explain different properties.

• True

• False

The shape of the liquids changes, because the particles ...........................................

• The particles are arranged in fixed positions.

• mass are identical.

• can vibrate on the spot.

• can move around.

Firefighter's cylinder is filled with an amount of .....................................to support him for several hours.

• nitrogen

• chlorine

• oxygen

• carbon dioxide

Why can all substances in the gas state be compressed or squashed?

• The particles are arranged in fixed positions.

• The particles are far apart.

• The particles hold together strongly.

• The particles move around.

What is a vacuum?

• A space with particles that are very close together.

• A space with no particles.

• A space with particles that are far apart.

• A space with particles that hold together strongly.

Why can a substance flow in its liquid and gas states but not in the solid state?

• The particles are far apart.

• The particles are arranged in fixed positions.

• The particles hold together strongly.

• The particles move around.

Dry ice chemical name is ...................................... in the solid state.

• carbon trioxide

• calcium dioxide

• carbon dioxide

• carbon monoxide

Dry ice in the gas state spreads out and mixes with the air, and takes the shape of its container because:

(choose two answers)

• The particles move around.

• The particles are arranged in fixed positions.

• The particles hold together strongly.

• The particles do not hold together strongly.