Which statement correctly describes this reaction? 1) It is endothermic and energy is absorbed.
2) It is endothermic and energy is released.
3) It is exothermic and energy is absorbed.
4) It is exothermic and energy is released.

Select all of the statements which are true. electrons are located in shells or orbits around the atom. electrons orbit slowly around the atom. electrons travel in one flat path around the nucleus of an atom. the valence of an atom is determined by the number of electrons in the atom's outermost shell.

Light waves can move through , but they travel fastest when they move through a(n) .

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.