What is the value for the potential energy for a n = 4 Bohr orbit electron in zeptoJoules?

The energy is 1.36 10³ zJ

Explanation:

The equation for hydrogram atom energy with the Bohr model is

Eₙ = - 13.606 / n² [eV]

This equation gives the result in electron volts that can be transformed to joule,

1 eV = 1.6 10-19 J

Let's calculate the energy and then reduce

n = 4

E₄ = - 13.606 / 4²

E₄ = 0.85 eV

E₄ = 0.85 eV (1.6 10⁻¹⁹ J / 1 eV)

E₄ = 1.36 10⁻¹⁹ J

Now we reduce to this submultiple of the correct unit

1 zepto = 10⁻²¹

1 J = 10 21 zJ

E4 = 1.36 10⁻¹⁹ J (10 21 zJ / J)

E4 = 1.36 10³ zJ

The energy is 1.36 10³ zJ