1.  For each statement decide if it is true or false.

• A liquid will sink when it is hotter than the liquid around it.

• Air becomes less dense and sinks when it loses its heat..

• Thermal convection happens in liquids and gases. .

• Thermal convection happens in solids. 

• Sea breeze is caused by thermal conduction. 

• Tea at the top of a cup is hotter than tea at the bottom of the same cup. 

   2.  How do convection currents in liquids and gases form?    

   3. Explain how a hot-air balloon rises.