Which phase change results in the release of energy

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.

Which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li

How many moles of sulfur dioxide are produced when 4.38 moles of oxygen completely react with iron (iv) sulfide