30 POINTS! PLEASE HELP.

Which of the following are two examples of ways that objects can have potential energy?

A. A boulder that is falling after being pushed off a cliff.

B. A Iron nail as it move towards a magnet.

C. A pebble in a slingshot before it has been shot.

D. A pebble traveling as it is shot with a slingshot.

A6.10 m nacl can be made by adding [x]g of nacl to a container and making the volume of water up to the 1.00 l line

In a spacecraft, the following reaction occurs: co2(g) + 2lioh(s) -> lico3(s) + h2o(i) (i attached picture of equation) how many liters of carbon dioxide will 4 moles of lithium hydroxide (lioh) absorb? (one mole of any gads occupies 22.4 l under certain conditions of temperature and pressure. assume those conditions for this equation.) 45l 6.0l 3.0l 34l

Compare and contrast physical changes with chemical changes.