What is the angular momentum of an electron in the ground state of a hydrogen atomand by how much does that angular momentum increase when the electron moves to thenext higher energy level?

In the nth orbit of the hydrogen atom, the angular momentum of the electron is mentioned as, Ln = nh/2π

In the case of the ground state, n = 1, thus, the angular momentum of the electron in the ground state will be,  

L1 = 1 h/2π

= (1) (6.626 × 10⁻³⁴J.s)/2π × (1kg.m².s⁻²/1J)

= 1.055 × 10⁻³⁴ kg. m²/s

For the first excited state or the next higher energy level, n = 2. Thus, the angular momentum of electron in ground state will be,  

L2 = (2) h/2π

= (2) (6.626 × 10⁻³⁴ J.s) / 2π × (1kg.m².s⁻²/1J)

= 2.11 × 10⁻³⁴ kg. m²/s

Now, the increase in angular momentum is as follows:  

L2-L1 = (2.11 × 10⁻³⁴ kg. m²/s) - ( 1.055 × 10⁻³⁴ kg. m²/s)

= 1.055 × 10⁻³⁴ kg.m²/s

c. 75.7

i think that is the right

it means there are 3 atoms of oxygen