In the physical science lab, kim and dawn added small pieces of magnesium to hydrochloric acid. they observed that bubbles formed, the test tube got hot, and the magnesium disappeared. what is a sign that a chemical reaction has taken place in this experiment? a. odor b. gas is produced c. magnesium appeared d. temperature decreased

The density of glycerin is 1.26grams/centimeter cubed . how many is this? use the conversion rates of and . express your answer to the correct number of significant figures.

Mrs. smith ordered a root beer float (vanilla ice cream + root beer). mrs. smith noticed that the three states of matter (solid, liquid, and gas) all existed simultaneously in her root beer float. a. identify each phase of matter in the root beer float. b. describe the particles of all three phases of matter in the root beer float. (how are the particles arranged and moving? ) c. identify one phase change you would see in a root beer float and described what causes this change.

Solar energy is energy from the sun that is converted into thermal or energy. a. nuclear b. mechanical c. electrical d. chemical