What determines the amount of chemical energy a substance has. 6th grade level

Which is the layer underground where all empty spaces are filled with a combination of air and water ?

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg

Which compound contain an iron with a 3+ charge