An ion has a positive or negative charge. While a covalent bond always has no charge, meaning it is neutral.
Answer:
Frecuency = 5,83x10⁻⁷ Hz
Explanation:
The equation that connects wavelenght and frequency is given by:
λ = c/ν
λ=wavelenght (expressed in lenght´s units)
c= speed of light (3x10⁸ m/sec)
ν=frequency (expressed in units of time⁻¹ or Herzt)
In our case, λ=5,14x10⁻⁷ m , so replacing in our previous formula, this gives us the final result of ν (frequency for green light) of 5,83x10¹⁴ Hz (or Herzt)
I looked up what is the molecular formula for Phosphine and got this: PH3
Hope this helps! Let my know if this was correct.