In terms of particles why doesn't liquid iodine conduct electricity?

What is the ph of a solution with a concentration of 5.2 × 10–8 m h3o+?

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

Iknow #2 is d. i just need to know why