Page 40 - Surviving Chemistry BFF Homework Helper and Test Prep Preview

Energy of an electron is quantized, meaning, it is specific for each energy level.

The equation below can be used to calculate the energy, En , of an electron in
a hydrogen atom if its principal energy level, n, is known.

-2.178 x 10 -18
En = ------------------ Joules
n
2

(c) E3 Scholastic Publishing

Light is a form of electromagnetic radiation that
c
travels at a of 3.00 x 10 m/sec.
8
= -----

Every electromagnetic radiation (different light colors)

is emitted at a specific ( ).
Frequency ( ) of light, in Hertz, indicates the
number of completed wave per second.

/;

When an atom absorb or release energy in the form

of electromagnetic radiation during electron transition

= h = ----
from one energy level to another, the energy change,

(in Joules), can be calculated using this equation.

.
= Planck’s constant, 6.63 x 10 -34 Joules sec.

= frequency of the radiation (1/sec or Hz)
= wavelength of the radiation (m)
8
= speed of light, 3.00 x 10 m/sec
44. Calculate the energy of an electron of a hydrogen atom in these three shells.

a) n = 1 b) n= 2 c) n = 3

-12
45. Violet light has a wavelength of 4.10 x 10 m. What is its frequency?

46. A helium laser emits light with a wavelength of 633 nm. What is the frequency of
the light?

14
47. Calculate the wavelength of radiation with a frequency of 8.0 x 10 Hz.

14
48. Green light has a frequency of 6.01 x 10 Hz. What is the wavelength?

49. Calculate the energy of a photon of radiation with a frequency of 8.5 x 10 Hz.
14

50. Calculate the energy of a gamma ray photon whose frequency is 5.02 x 10 Hz.

20

-7
51. Calculate the energy of a photon of radiation with a wavelength of 6.4 x 10 m.

-11
52. What is the energy of light whose wavelength is 4.06 x 10 m?

53. An FM radio station broadcasts at a frequency of 107.9 MHz. What is the
wavelength of the radio signal?

50 Copyright © 2014. E3 Scholastic Publishing. SurvivingChem.com