Which evidence has led scientists to conclude that there are different layers within earths interior

The slope of a velocity time graph over any interval of time gives the during that interval

If you put a helium-filled balloon in the refrigerator, what will happen?

Which of the following is part of the explanation or description of electromagnetic waves? (select all that apply) a. electrically charged molecules in a medium transfer their energy to nearby electrically charged molecules. b. a changing electric field causes a changing magnetic field. c. magnetic molecules in a medium transfer their energy to nearby magnetic molecules. d. a changing magnetic field causes a changing electric field.