Light and Energy

Question 1

Light

Answer 1

c = λv

c = speed of light
λ = wavelength
v = frequency

Question 2

Energy

Answer 2

E = hv

E = energy
h = Planck’s constant
v = frequency

Question 3

Energy of a mole of photons with a λ of x?

Answer 3

E=(hc)/λ x Avogadro’s #.

c = speed of light
h = Planck’s constant
λ = wavelength

Question 4

Hydrogen Atom

Answer 4

Bohr Model

-Electron must have specific energy based on attraction to nucleus & motion around nucleus.

E_n=R_H/n^2
-R_H = Rydberg constant (2.180 x 10^-18 J)
-n = number of the energy level.
E = 0 when electron is completely separated from nucleus.

Question 5

Photon Energy

Answer 5

Equal to the difference in energy between energy levels. Delta E = E_hi-E_low

v = R_H/h(1/N^2_low-1/N^2_hi)
-for frequency.
-R_H = Rydberg constant (2.180 x 10^-18 J)
-h = Planck’s constant (6.626 x 10^-34 J*s)

Question 6

Visible to human eye

Answer 6

4×10^-7 to 7×10^-7