Help with Chemistry please!!

Question

The following questions deal with the nature of light and color. (Enter your answers using scientific notation.)

(a) A photon has a wavelength of 440. nanometers (nm). What is the length in meters?

 m

(b) What is the frequency of this photon?

 s⁻¹

(c) What is the energy of this photon?

  J

Answer 1

(a) To convert nm (nanometers) to m (meters), you need to know the conversion factor of

1 m = 1x10⁹ nm or 1x10-⁹ m = 1 nm

440 nm x 1 m / 1x10⁹ nm = 440x10^-9 m = 4.40x10^-7 m

(b) Given the wavelength of 4.40x10^-7 m and asked for the frequency, we can use the formula

c = λν or c = wavelength x frequency where c = speed of light = 3x10⁸ m/sec

3x10⁸ m/sec = 4.40x10^-7 m x ν

ν = 3x10⁸ m/sec / 4.40x10^-7 m = 6.82x10¹⁴ s^-1

(c) The energy of a photon with this frequency (ν) is E = hν

E = energy = ?

h = Planks constant = 6.626x10^-34 Jsec

ν = 6.82x10¹⁴ s^-1

E = (6.626x10^-34 Jsec)(6.82x10¹⁴ s^-1)

E = 4.52x10^-19 J