What is the energy of an electron in the 2s orbital of a hydrogen atom?

E = 2.180 x 10^-18/N2 Joules.

To determine the energy of an electron in the 2s orbital of a hydrogen atom, we can use the formula for the energy of an electron in a hydrogen atom:

E = -R (Z^2 / n^2)

Where:
- E is the energy of the electron
- R is the Rydberg constant (approximately 2.18 × 10^-18 J)
- Z is the atomic number of the nucleus (which is 1 for hydrogen)
- n is the principal quantum number of the electron's energy level

In this case, the 2s orbital corresponds to the principal quantum number n = 2.

Now we can calculate the energy of the electron in the 2s orbital of a hydrogen atom:

E = - R (Z^2 / n^2)
= - (2.18 × 10^-18 J) (1^2 / 2^2)
= - (2.18 × 10^-18 J) (1 / 4)
= - 5.45 × 10^-19 J

Therefore, the energy of an electron in the 2s orbital of a hydrogen atom is approximately -5.45 × 10^-19 J. The negative sign indicates that the electron is bound by the attractive force of the hydrogen nucleus.