Which statement explains the process of a chemical reaction? a. substances are mixed together, producing a homogeneous mixture. b. reactants react to produce new substances known as products. c. substances are mixed together, producing a heterogeneous mixture. d. products combine to produce new reactants.

Which statement describes covalent bases? they have hydroxide ions. they produce hydrogen ions. they are often amines. they are named the same as ionic compounds.

The human eye contains a molecule called 11-cis-retinal that changes shape when struck with light of sufficient energy. the change in shape triggers a series of events that results in an electrical signal being sent to the brain that results in vision. the minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kj/mol.

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?