10 Flashcards
Light is
Pure energy and has no mass
Light behaves much like
A wave of
The top of the wave is the
The bottom of the wave is the
Crest
Trough
Distance between each trough or each crest is
Represented by the symbol
Measured in
A wavelength
Lambda
Meters
Frequency
Units? Symbol?
of wavelengths that pass a given point per second
Hertz HZ
Nu (v)
Velocity
Wavelength * Frequency
What is a photon
Streams of tiny packets of energy
Light waves are also known as
Electromagnetic Radiation
ROY G BIV
Which way does energy go
Less energy ——- More Energy
E-M
Electromagnetic radiation
Most EM/light comes from ___ and is a result of _____
Within the atom
Excited electrons falling back to ground state
How do electrons move to higher energy levels. What is this called
By absorbing distinct amounts of energy called Quanta
The excited state
Electrons in the excited state are
Therefor
Unstable
They fall back to the “ground state”
What electrons are most stable
Those in the lowest energy level
When electrons fall
How fall it falls
It gives off EM radiation/light
Determines what type of radiation is emitted
Hydrogen in an excited state
emits a photon to return to a lower energy state
Hydrogen only emits
Certain colors of visible light when it releases a photon
We only see
Selected colors, not those that give off white light.
Hydrogen has discrete
energy levels that are quantized
Every hydrogen
Falls in the same ways and gives off the same light.
Hydrogens energy levels are quantized
What does quantized mean
A set of steps, only certain values are allowed.
Bohr model
Only works for
Is it correct
Electrons orbit the nucleus
Different orbits equal different energy levels
Hydrogen
No
Wave mechanical model
Electrons do not orbit the nucleus
Predicts the probability of finding an electron at given points around the nucleus.
With the wave mechanical model location of electrons is shown using a
Probability map.
Orbital
Do they have exact size
Contains
Probability map of an electron
No
90% total electron probability
Principle energy levels
Discrete energy levels electrons can occupy
Lower number lower energy
Lower number less distance from nucleus/closer
Each energy level can be divided into
More energy =
Sub levels
More sub levels
What are the 4 sub levels
S p d f
How many orbitals are in each sub level
How many electrons per orbital
S 1
P 3
D 5
F 7
2 electrons per orbital
Number of sublevels ____ number of energy levels
Equals
What is the shape of each orbital
S sphere
P Dumbell
D Clover
F Hard to visualize
Electrons want to be
Electrons have
As close to nucleus as possible
Spin
Wave mechanical model can be applied
To all atoms
Pauli Exclusion Principle-
2 electrons can occupy an orbital only if they have opposite spin
Electron configuration
The way electrons are arranged around the nucleus Predicts
Ionization energy
More attraction
Energy required to remove outermost electron
Harder to remove
What does the atomic mass on the periodic table represent
weighted average mass of all the naturally occurring isotopes of that element
