Module 5: Electromagnetic Energy and the Bohr Model of the Atom Flashcards
The energy transmitted by waves that have two components: electric and magnetic field
Electromagnetic Energy
Range of energies that electromagnetic radiation can comprise
Electromagnetic Spectrum
How electromagnetic energy travels through space
Wave
An oscillation or periodic movement that can transport energy from one point in space to another and need not be restricted to travel through matter
Wave
characteristics of wave
Wavelength, frequency and amplitude
Distance between two consecutive peaks or troughs
Wavelength
The number of wave cycle that pas a specific point in space in a specified amount of time
Frequency
This is related to the intensity of the wave
Amplitude
This consist of an electric field oscillating in step with a perpendicular magnetic field, both are perpendicular to the direction of travel
Electromagnetic waves
Speed of a wave through a vacuum
2.998 x 10e8 m/s
Formula for speed of a wave
c = wavelength x frequency
As wavelength increases, what happens to the frequency and energy?
decreases
Who proposed that energy was quantized meaning it could only be absorbed or emitted in a discrete quantities
Max Planck
Formula for Quantized energy
E = h x frequency
Value of planck’s constant?
h = 6.626 x10e-34 Js
States that electron could be ejected from the clean surface of a metal when light having a frequency greater than the threshold frequency was shone on it
Photoelectric Effect
Does the incident light need to have more energy than binding energy to eject an electron from a metal?
Yes
Formula for Quantized Energy with speed of wave
E = (h x c) / wavelength
This happens when a gas is excited at a low partial pressure using an electrical current or heating it
Line Spectra
What did Bohr ignored to resolve the atomic paradox for his model of the atom?
classical electromagnetism
This school of thought’s prediction was that the orbiting electron in an element would continuously emit light
classical electromagnetism
In 1913, he assumed that electron orbiting the nucleus would not normally emit radiation but it would emit or absorb a photon if it moved to a different orbit
Niels Bohr
as the energy level (n) decreases, what happen to the absolute value of En?
Increases
The more negative the energy (En) the closer it is to what state of the electron?
Ground state
Formula for energy of an Electron if n>1
En = -k/n e2
the constant k has a value of ?
k = -2.18 x 10 e-18 J
When is matter most stable?
With the lowest possible energy for it
State of electrons in an atom when they have the lowest energy possible
Ground Electronic State
State of electrons when an atom received energy from an outside source causing it to move in a higher energy
Excited Electronic State
Formula for Energy (delta E) in relation to n
delta E = k (1/n final e2 - 1/n initial e2)
If delta E is negative, what happened to the light and orbital?
It emitted light and went from a higher orbital to a lower orbital
If delta E is positive, what happened to the light and orbital?
It absorbed light and went from a lower orbital to a higher orbital
