What is the nitrogen cycle? what parts do plants play in it?

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.

Why is nh3 classified as a polar molecule

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion