Explain how the density of a substance varies with change in temperature.

How can you determine the density of an irregular solid with the help of a measuring cylinder?

Explain why solids have greater densities than liquids and liquids have greater densities than gases.

Explain the procedure to determine the density of an unknown liquid using a relative density bottle.

A rectangular piece of wood measures $4 \mathrm{cm}$ by $6 \mathrm{cm}$ by $8 \mathrm{cm}$ and has a mass of $20 \mathrm{g}$. What is the density of the piece of wood? Will this piece float in water or not?