Why the climate is colder close to the north and south poles than it is at the equator

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?

Define dew point. i am writing this part to be able to ask the question

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.