Which models could be used to demonstrate the law of conservation of matter? Select all that apply. Select one or more correct answers

I'm trying if I got it right before I submit it

Which element is least likely to undergo a chemical reaction

Why do oxygen have a strong attractive force for electrons

Generally, observed behavior that can be formulated into a statement, sometimes mathematical in nature, is called a(n): a. observation. b. measurement. c. theory. d. natural law. e. experiment.