Please help me understand this!

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.

What term is applied to a scientist who studies ancient life, including animal and plant fossils a. anthropologist b. dendroclimatologist c. geophysicist d. paleontologist

Each step in the following process has a yield of 70% ch4 + 4cl2 yield ccl4 +4hcl ccl4 + 2hf yield ccl2f2 + 2hcl of 4.50 mole ch4 reacts what is the total amount of hcl produced