(07.01 LC) Which of the following happens during an exothermic chemical change? (4 points)
Net energy increases.
Heat is absorbed.
Net energy remains constant.
Heat is released.

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.

Suppose that some of the compound spilled out of the crucible after it was heated. would that cause the percent by mass of water in the compound determined by the experiment to be too low, too high, or unchanged? briefly explain your answer.