What elements cycle between living and non-living organisms?

Can someone me with questions 15 to 17 plz.

*will mark you brainliest + 15 points ** why does the equilibrium of a system shift when the pressure is increased? a. to maximize the stress on the system b. to stop restoring equilibrium to the system c. to increase the total moles of gas in the system d. to decrease the total moles of gas in the system

What is a difference between a mixture of elements and a mixture of compounds