Question

the electromagnetic spectrum and electronic transitions
frequency of light
the longest wavelength of light with enough energy to break an oxygen-oxygen double bond is 240. nm.
calculate the frequency of the light in s⁻¹.
useful equations and constants:
$c = \lambda\
u$
$e = h\
u$
$c = 3.0 \times 10^8$ m/s
$h = 6.626 \times 10^{-34}$ j·s
avogadros number $= 6.02 \times 10^{23}$ mol⁻¹
what is the frequency of light with a wavelength of 240 nm?
8.00×10⁷ s⁻¹
1.25×10⁶ s⁻¹
1.59×10⁻⁴⁰ s⁻¹
1.25×10¹⁵ s⁻¹

Explanation:

Step1: Convert nm to meters

$240\ \text{nm} = 240 \times 10^{-9}\ \text{m} = 2.4 \times 10^{-7}\ \text{m}$

Step2: Rearrange formula for frequency

From $c = \lambda
u$, solve for $
u$: $
u = \frac{c}{\lambda}$

Step3: Substitute values and calculate

$
u = \frac{3.0 \times 10^8\ \text{m/s}}{2.4 \times 10^{-7}\ \text{m}} = 1.25 \times 10^{15}\ \text{s}^{-1}$

Answer:

1.25×10¹⁵ s⁻¹ (Option: 1.25×10¹⁵ s⁻¹)