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 an electron in a hydrogen atom is present when its energy is -76.4 kcal/mol, we can use the formula derived from the Bohr model of the hydrogen atom. Here’s a step-by-step solution:

### Step 1: Understand the Energy Formula
The energy of an electron in a hydrogen atom is given by the formula:
\[ E = -\frac{13.6 \, z^2}{n^2} \, \text{eV} \]
where \( z \) is the atomic number (for hydrogen, \( z = 1 \)) and \( n \) is the principal quantum number (the orbit number).
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