Which of the following are examples of exponential decay? select all that apply.

a vehicle depreciates 13% each year.
a tree is doubling in height each year.
an investment earns a 5% interest each year.
air pressure decreases 12% for every 1000 meters in height.
the population of a town is growing at an annual rate of 3.5%.
a retirement account decreases by $12,000 each year.
a radioactive element has a decay rate of 10%.