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

a.) travels faster in solids because the particles are closer together.

air is a gas water is a liquid