What are the three main groups of mollusks? Give an example of each and explain the characteristics of each animal that can be used to classify it. Sample Gastropods: A snail is a kind of gastropod. It has a single shell. Snails move along on their foot and obtain food using their radula. Bivalves: an oyster is an example of a bivalve. Oysters have two shells, are filter feeders, and do not move very much. They will produce pearls to protect themselves from irritants in their shells. Cephalopods: A squid is an example of a cephalopod. Squid have tentacles, a beak to crush their prey, and radula to strip the flesh from their prey. They also have large eyes, a complex nervous system, and move by jet propulsion.

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.