Which is a characteristic of weak acids and weak bases? Ka and Kb values of weak acids and weak bases are small.
Forward reactions of weak acids and weak bases are favored.
Dissociation of weak acids and weak bases is nearly complete.
Many H+ or OH– ions are present in their solution.

Explanation is in the file

tinyurl.com/wpazsebu

The answer is A. Ka and Kb values of weak acids and weak bases are small.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.