A chemical reaction in which the products are a lower energy than the reactants is said to be: O a. Impossible
O b. Reversible
O c. Endothermic
O d. Exothermic

Which piece of equipment would me most useful for measuring the volume of some water? a. pan balance b. graduated cylinder c. tweezers d. flask quick

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

Classify this reaction: 2al+n2-> aln.