Trade-offs - It represent the the amount of one good that is to be given away to get some amount of other good.
Scarcity - It implies shortage
marginal analysis implies evaluating benefits for each additional unit .
Consumer behavior implies how the consumer behaves wrt to changes in the price and income. Demand represents the consumption given the prices.
Consumer surplus represents difference between the willingness to pay and the price paid.
Can anyone help me to write the definition economic concept : trade offs, scarcity, marginal analysis,...