20. An aqueous solution that has a hydrogen ion
concentration of 1.0 x 10-8 mole per liter has a pH of
A) 8, which is acidic B) 8, which is basic
C) 6, which is basic D) 6, which is acidic
b

I think the anwser is A

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