Calculate the wavelength of the photons emitted by hydrogen atoms when they undergo transitions from n = 4 to n = 3.

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

Which is a chemical property of iron? a. it forms iron oxide (rust) when exposed to moisture and air. b. it is a gray–black metal that is hard to the touch. c. it has a melting point of 2795°f (1536°c). d. it is a good conductor of heat

Aradio signal from a gps satellite take only about 0.067 seconds to reach a gps reciever. if the speed of light is about 300,000km/s, then approximately how far away is the reciever from from the satellite?