Questions: What is an intermediate? - A local maximum on the energy diagram. - A point on the reaction pathway that has a discrete minima. - A point half-way between the starting materials and products. - The highest energy compound on an energy diagram.

The answer is the second one: A point on the reaction pathway that has a discrete minima.

Explanation for each option:

1. A local maximum on the energy diagram: This describes a transition state, not an intermediate. A transition state is a high-energy state that occurs during the transformation from reactants to products.
2. A point on the reaction pathway that has a discrete minima: This is correct. An intermediate is a species that exists at a local minimum on the energy diagram between the reactants and products. It is more stable than the transition state but less stable than the reactants or products.
3. A point half-way between the starting materials and products: This is incorrect. An intermediate is not necessarily halfway between the reactants and products; it is defined by its position at a local minimum on the energy diagram.
4. The highest energy compound on an energy diagram: This describes a transition state, not an intermediate. The highest energy point on the energy diagram corresponds to the transition state, which is a temporary state during the reaction.

Summary: An intermediate is a point on the reaction pathway that has a discrete minima, indicating a relatively stable species formed during the reaction process.