I need to know the measurements of this to the appropriate amount of significant figures

Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in the n=3 level to an orbital in the n=7 level.

Ants live on acacia trees in south america. the ants feed on sugars secreted by the trees. the trees provide room for the ants to live. the ants sting any other insect or animal that comes to eat the trees. what type of relationship is this?

Mercury turns to a vapor at 629.88 k. how much heat is lost when 75.0 g of mercury vapor at 650 k condenses to a liquid at 297 k?