Lead is the Carbon family of the periodic table.
A catalyst is a substance that increases the rate of a chemical reaction by lowering the activation energy without itself being consumed by the reaction.
Natural selection is the process in which a weaker, or less advantaged animal loses something to a stronger, more advantaged animal. For example, a frog with a broken leg probably will not get to mate while a healthy frog will. Evolution is the process of an animal gradually changing over the generations biologically. An example of this is the theory that humans slowly evolved from monkeys, gradually becoming more and more human like.
The reaction would produce bubbles of gas.
We can prepare 3-5 test tubes of acid with increasing concentrations. Then, we add antacid tablets to each and note the time taken for the tablet to dissolve and stop producing bubbles. The lesser the time taken, the greater the rate of reaction.