Can someone explain what composition makes uncooked sliced carrots sink and parsnips float in a pan of water?

Parsnips have a much looser structure, which carries more air, so the specific gravity is lower than carrots, which are much denser.

Thank you, Snoopy! I do my best.

Carrots take longer to cook too, I remember using a slow cooker and had to parboil the carrots before adding or the meat would be lovely and tender and the carrots still hard........

its also down to the amount of sugars affecting the density of the tissues.

Oh is that what it is? Doesn't surprise me.......

Thanks - SBG would not the density difference also alter the air difference as Gattina suggests and contribute to the bouyancy?