List the metals given in the table below in order of their increasing density.

What is meant by density?

A block of metal has a volume of $20 {\mathrm{cm}}^3$ and a mass of $158 \mathrm{g}$. Which metal is it?

Now list the metals in order of reactivity.

The most reactive metal in the list has a density of _____ $\mathrm{g}/{\mathrm{cm}}^3$? Enter only the value.

The least reactive one has a density of _____.

Does there appear to be a link between density and reactivity? If yes, what?

Low-density metals are used for vehicles; as they save money on fuel and road repairs. Explain why.

Which of the low-density metals below is the most suitable for vehicles? Why? Give reasons.