Explanation:

- Costs and benefits: These refer to the perceived rewards and expenses involved in a social exchange. Both parties weigh these to determine the value of the relationship.

- Unvoiced expectations and obligations: Social exchanges often involve unwritten rules and expectations that guide behavior and obligations between the parties.

- Procedural justice: This refers to the fairness of the processes used in decision-making. It is often applied in legal and organizational contexts, not typically part of social exchange relationships.

- Unequal power: In social exchange relationships, one party may hold more power, influencing the dynamics of the relationship and the distribution of costs and benefits.