What is the total number of atoms in a 75 g sample of zinc?

State one important difference between a physical change and a chemical change?

How does a sample of helium at 15 degree celsius compare to a sample of helium at 215 k? a) the helium at 15 degrees celsius has a higher average kinetic energy that the sample at 215 k. b) the helium at 15 degrees celsius has lower nuclear energy that the sample at 215 k. c) the helium at 15 degrees celsius has slower- moving atoms that the sample at 215 k. d) the helium at 15 degrees celsius has smaller atoms than the sample at 215 k.

Ethyl alcohol, also known as ethanol, has a density of 0.79 g/ml. what is the volume, in quarts, of 1.95 kg of this alcohol?