What is the energy of a photon with a wavelength of 245 nm

What is the chemical formula of the following compound

What mass of carbon dioxide is produced from the complete combustion of 4.50×10−3 g of methane?

Read these sentences from the text. near the equator, the tropics receive the most rain on a consistent basis. as a result, the fresh water falling into the ocean decrease the salinity of the surface water in that region. [. .] . . as the salt content of sea water increases, so does its density. what can you infer about how rain affects the density of surface water near the equator?