Find the frequency of light f radiated by an electron moving from orbit n1=2 to n2=1 inside of a he + ion. express your answer in hertz to three significant figures.

According to the Bohr model of a hydrogen atom, the frequency of light radiated by an electron moving from an orbit n₁ to an orbit n₂ corresponds to the energy level difference between n₁ and n₂ of:

E = E ₀ (1/n₁² - 1/n₂²)

Where,

E₀ = mₓZ²e⁴/32π²∈₀h²

Where,

mₓ is the electron mass

Z is the atomic number

e is the magnitude of the electron charge

∈₀ is the permittivity of free space

h is Planck's constant divided by 2π.

In the case of hydrogen (Z = 1).

∈₀ = - 13.6 eV

The frequency of light f radiated by an electron = 9.860*10¹⁵ Hz