Describe the relationship between these pairs of compound as: isomers, identical, or unrelated

A.) CIS/Trans isomers
b.) constitutional isomers
c.) identical
d.) constitutional isomers
e.) identical

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water