Molecules and matter Quiz

The correct equation for density is…

• $density\ =\ mass\ \times volume$

• $density\ =\ mass\ \times\ area$

• $density\ =\ \frac{mass}{volume}$

• $density\ =\ \frac{mass}{area}$

A body of water of an area of 2 m² and a depth of 4 m, has a mass of 8000 kg. Calculate the density of water.

• 1 000 kg/m³

• 4 000 kg/m³

• 16 000 kg/m³

• 128 000 kg/m³

In which state can the volume be changed by compression?

• liquid

• gas

• solid

• none of the above

Changes of state are examples of…

• property changes

• energy changes

• chemical changes

• physical changes

Which statement about liquids is FALSE?

• liquid particles move randomly

• liquids can be compressed

• liquid particles are always in contact with each other

• liquid particles are more energetic than solid particles

Complete the following sentence.

When a substance changes state, its mass stays the same because…

• the energy of the particles stays the same.

• the volume of the particles stays the same

• the density of the particles stays the same

• the number of particles stay the same

sublimation happens when...

• a gas changes into a solid

• a solid changes into a gas

• a solid changes into a liquid

• a liquid changes into a gas

The temperature at which a solid changes to a liquid is called its…

• melting point

• boiling point

• freezing point

• sublimation point

What is needed to melt a solid or boil a liquid?

• vaporisation

• change of temperature

• an increase in energy

• chemical change

Evaporation can occur at the surface of a liquid when its temperature is…

• below its melting point

• equal to its freezing point

• equal to its melting point

• below its boiling point