How do the electrons absorb energy in an discharge tube that is used for produce an emission spectrum?

Question

When there's hydrogen in a discharged tube it produces an emission spectrum, emitting energy(photons). (Eg:-When an electron jumps from 3rd energy level to 1st energy level, the electron emits a photon) So that particular electron must have absorbed energy before the emission of photons (in order to [electron] be in the 3rd energy level.)

1. How do the electrons absorb energy in a discharge tube [do electrons absorb photons in the discharge tube and then jump to higher energy levels, or is there any other way that electrons to be in the 3rd energy level]?

2. Do electrons of hydrogen atoms in the discharge tube, absorb energy from electro-magnetic waves[if the tube produces]? Or do the electrons absorbs energy from another source?[ I need an explanation of what happens in the discharge tube and how the electrons in the 1st energy level jumped to higher energy levels before the emission of photons making an emission spectrum]

3. In this PhET simulation I saw that when an electron collided with a hydrogen atom, it's electron jumped to a higher energy level and then jumped back to the 1st energy level emitting a photon, how did the electron absorb energy from the electron in the discharged tube?

Answer 1

your number 3 is the right explanation m in the tube it ist the fast electrons which collide withe the molecules and get the molecules exited or even ionized. This is the source of most light you see, for example in a flame also.