Metals and nonmetals used in backpacks

Which is true of a liquid? it has a definite volume but not a definite mass.it has a definite mass but not a definite volume.it has a definite volume but not a definite shape.it has a definite shape but not a definite volume.

As light moves from one material into the next, which of the following affects how much the light waves will refract, or bend? angle at which the ray strikes the medium color of the material density of the material temperature of the light wave

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.