After an electron releases energy (in the form of light), causing one of its electrons to move back to a lower energy level, that electron is said to be in the . A) the nucleus
B) the ground state
C) an excited state
D) an outer orbit

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.

When an object falls through the air and encounters air resistance its overall speed will be than if it had not encountered air resistance? (one word answer)

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.