Why do we heat the test tube in a glass beaker during a chemistry experiment and not directly over a flame?

Which statement best describes the liquid state of matter? a. it has definite shape but indefinite volume. b. it has definite shape and definite volume. c. it has indefinite shape and indefinite volume. d. it has indefinite shape but definite volume.

What is the equation for calculating rf values

Which of the following has expanded our knowledge of the universe beyond our solar system the most? a. manned space travel b. the hubble space telescope c. the pioneer and voyager missions d. the international space station