If an electron in H atom has energy of `-76.4` kcal `"mol"^(-1)` .The orbit in which the electron is present is

Options

A. Ist
B. 2nd
C. 3rd
D. 4th

Explanation

To determine the orbit in which the electron of a hydrogen atom is present, given its energy of -76.4 kcal/mol, we will follow these steps:

### Step 1: Convert energy from kcal/mol to joules
We know that:
- 1 kcal = 4180 joules
- 1 mole = Avogadro's number (approximately \(6.022 \times 10^{23}\))

The energy in joules can be calculated as follows:
...