What is the name of the economic concept that describes the value of the second-best item or activity that is given up when the best item or activity is chosen?

Opportunity cost.

Explanation:

Opportunity cost is defined as the cost incurred when and individual carries out an activity and not another one. It is the value of the second best item that is given up.

For example if a person has a choice of going to the movies instead of working. The monetary cost of going to the movie is the amount he will pay for the tickets, however economists also consider the cost of the foregone alternative that is working and earning a wage.

So the opportunity cost is the wage that would have been earned if he had gone to work.

the federal government of the united states was established by the constitution. us is a presidential republic. the president is head of state, head of government and of a two party legislative and electoral system. the supreme court balances the powers of the federal and the state government. yhe executive branch is headed by the oresident. there are two chambers of congress, the senate and the house of representatives. judicial power is exercised by the judicial branch (or judiciary), comprised of the supreme court and lower federal courts. the judiciary's function is to interpret the   constitution as well as the federal laws and regulations.

the language of nature was a manifestation from god as he said "let there be light" and there was light the world began to assume visible, comprehensible form.

what ever we know now think of the old vision of creation we can be sure that with out the speaking of word -without language- we would have no science today with its striking power to illuminate the world.