Question

What is the energy of an electron that is revolving in the second orbit of the hydrogen?
1. - 1.51 eV
2. - 3.4 eV
3. - 13.6 eV
4. - 15.1 eV

Answer 1

Correct Answer - Option 2 : - 3.4 eV

CONCEPT:

• Every electron revolves around the nucleus in the orbits.
• The nucleus is positively charged and the electrons that revolve around the nucleus are negatively charged, so they attract each other.
• Bohr was the scientist who gave an explanation of Hydrogen.

• Bohr's model of hydrogen is based on the assumption that electrons travel in specific shells, or orbits, around the nucleus.
• Bohr's model calculated the energy of an electron revolving on different orbits (n):

E = \(- \frac{13.6}{n^2}\) eV

Where n is the orbit number in which the electron is moving.

EXPLANATION:

Given that the electron is in 2nd orbit; n = 2

• The energy of an electron at nth orbit is given by:

\(\Rightarrow E =- \frac{13.6}{n^2} \, eV\)

• So, the energy of an electron at the 2^nd orbit will be:

\(\Rightarrow E=- \frac{13.6}{2^2}=-3.4 \, eV\)

​Hence the correct answer is option 2.