The warming of the thermosphere (the upper level of the atmosphere) is caused by

Wavelength of photon is 80.1 nm and it belongs to UV region.

Explanation:

If wavelength of required photon is then-

where, is avogadro constant, h is plank constant, c is velocity of light.

So,

or, =

or, = 80.1 nm

As wavelength of photon lies between 1-100 nm therefore the photon belongs to UV region of electromagnetic spectrum.

Your first flip has a 1/2 or 50% chance of getting tails. In order to get 2 tails in a row you have to get tails first and then again. The first flip is 1/2 and the second one is another 1/2. Combined you have a 1/4 chance of getting 2 tails in a row.

Each time you flip you have 1/2 a chance, but when you look at all the flips at once, each consecutive flip of the same side has a smaller probability.