What is Bohr’s model?
electrons moving in fixed paths, or orbits, around the nucleus.
It helped explain how atoms give off or absorb light.
Shortcomings of Bohr model?
Only works well for simple atoms like hydrogen. It cannot explain atoms with many electrons. It also does not match the modern idea of electrons as clouds, not fixed paths.
Excited Electrons
- Electron absorbs energy
- Jumps to higher energy level (moves away from nucleus)
Electrons Absorb Energy
-Further away from the nucleus → requires energy to overcome the attractive force between + and -
-Referred to as the “excited” state → unsable! e- immediately releases the E it absorbed
-Amount of E needed to go from ex: n=2 → n=3 differs between elements because different strength of attractive force to overcome based on # of p+/e-
Electrons Release Energy
-Closer to the nucleus
- going to ground state
e- “jump up” to higher energy levels when they ______ energy.
absorb
e- “fall down” to lower energy levels when they ______ energy.
release
yes or no e- travel in defined orbits around the nucleus
No longer supported → clouds of probability re: Shrodinger
yes or no e- are associated with discrete energy levels
Supported → “PEL” principle energy levels: n=1, n=2, etc… n is a whole #. The amount of E at the PEL is DIFFERENT for each element because of the difference in e-/p+ makes a different strength of attractive force to overcome.
yes or no e- can not exist between energy levels
Supported → “poof” Analogy: teleporting → entanglement, huge for future of quantum computing/mechanics
Order of Electron excitation
- Ground State
- Absorbs energy
- Excited State
- Release Energy (see light)
- Ground state
Of the 7 types of EM waves, which do we have biological “detectors” for?
visible
Of the 7 types of EM waves, which has the greatest amount of energy?
gamma
Of the 7 types of EM waves, which has the greatest frequency?
gamma
Of the 7 types of EM waves, which has the largest wavelength?
radio
Of the 7 types of EM waves, which is considered dangerous to humans if exposed to?
uv, x-ray, gamma
Energy, frequency, and wavelength relationships
Energy and frequency are directly related — if frequency goes up, energy goes up.
Wavelength and frequency are inversely related — if wavelength goes up, frequency goes down.
What can you infer about the transition that emitted a 400 nm wave compared to the transition that emitted a 550 nm wave?
That means the 400 nm transition has higher frequency and higher energy.
The 550 nm transition has lower frequency and lower energy.
Orders EM Spectrum
(low E, low F, high wavelength) Radio, microwave, infrared, visible (ROYGBIV), ultraviolet, x-ray, gamma ray (high E, high F, low wavelength)
What is PEL?
-Principle Energy Levels
-For Bohr and Quantum
-n=1,2,3…
-How far from nucleus associated with amount of energy
What is an orbital?
-Only quantum
-Regions of space where Electron is most likely to be found. s,p,d,f orbitals
-s=lowest energy
-f=most energy
n=1
s orbital
n=2
s,p orbital
n=3
s,p,d orbital
