Answer:
The "2" tells us that there are 2 hydrogen atoms in this compound.
Explanation:
I believe it is lithosphere
The De Broglie wavelength of the electron is

And we can use De Broglie's relationship to find its momentum:

Given

, with m being the electron mass and v its velocity, we can find the electron's velocity:

This velocity is quite small compared to the speed of light, so the electron is non-relativistic and we can find its kinetic energy by using the non-relativistic formula:
The basic relationship between frequency and wavelength for light (which is an electromagnetic wave) is

where c is the speed of light, f the frequency and

the wavelength of the wave.
Using

and

, we can find the value of the frequency:
In a series circuit the total current is the same throughout resistors and so:

The voltage is distributed throughout the resistors and so:

and the total resistance can be calculated by adding up the resistors resistance:

First thing is to calculate the total resistance and so:

And by Omh's law V=IR we have:

And so the total current of the circuit is 1.2 amps i.e. 1.2 A.