It takes 36 minutes for 100-grams of a radioactive substance to decay to 25-grams. What is the half-life of this substance?

Iwll give extra points to who gets this for ! what type of reaction is this? ?

7. what temperature is need to just dissolve 50 g of nh4cl in 75 g of water? '

Calculate the ratio of h+ ions to oh– ions at a ph = 7. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 7. are they the same? why or why not? record your comparison in table a. what is the concentration of h+ ions at a ph = 7? mol/l what is the concentration of oh– ions at a ph = 7? mol/l what is the ratio of h+ ions to oh– ions at a ph = 7? : 1