Classify each of the following as an element, a compound, or a mixture:
(a) copper
(b) water
(c) nitrogen
(d) sulfur
(e) air
(f) sucrose
(g) a substance composed of molecules each of which contains two iodine atoms
(h) gasoline

Fugu, also known as puffer fish, is a sushi delicacy that can also be lethal. puffer fish contain a powerful toxin that can kill an adult a few hours after ingestion. sushi chefs who prepare fugu must be specially trained because any contamination of the toxin-free areas of the fish can be deadly. recently this toxin has been put to good use, as scientists have discovered that a purified form of it can treat severe pain in cancer patients. this recent scientific discovery would fall under which area of chemistry? applied biochemistry pure organic chemistry pure physical chemistry applied inorganic chemistry

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

What is the average rate of the reaction between 10 and 20 s?