19. A drug has a blood plasma concentration of 20 mcg/mL. Ten hours later, the plasma concentration is 5 mcg/mL. This drug has a half-life of
hours.

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.

How will the emission of an alpha particle affect the atomic number of an atom

Why do electrons further from the nucleus have more energy