Chapter 7 Flashcards
The vertical distance from the midline of a wave to the peak or trough
Amplitude
The number of waves that pass through a particular point in 1 second
Frequency
The speed of a wave
U = lamda x v
Proposed that visible light consist of electromagnetic waves
Maxwell 1873
In the visible light consist of electromagnetic waves…(2 components)
Electric field component and magnetic field component
Perpendicular to one another
The emission and transmission of energy in the form of electromagnetic waves
Electromagnetic radiation
Speed of light
3.00x10^8 m/s
What we can see small part of electromagnetic spectrum
400-700 nanometer
Visible light
Electro attic radiation
Lamda x v =c
A photon has a frequency of 6.0x10^4 Hz. Convert into wavelength
Lamda = c/v
3.00x10^8 m/s / 6.0x10^4 Hz
Convert to nanometer
What did max planch (1900) discover?
-when solids are heated, they emitted electromagnetic radiation over a wide range of wavelength
Radiant energy emitted by an object at a certain temperature depends on its____
Wavelength
Energy is emitted or absorbed in discrete units called____
Quantum
Planch’s constant
h=6.63x10^-34 Js
Photoelectric effect 1905
- Einstein
- metals emit electrons when exposed to light
- light has both wave nature and particular nature
A particle of light
Photon
Finger prints for atoms
Line spectra
-excited by a high energy discharge, the light will pass through a prism
Bohr’s model of the atom 1913
- electrons can only have specific (quantinize) energy values
- light is emitted as electron moves from one energy level to a lower energy level
En=-RH(1/n^2)
What is n and R?
R= rydburg constant 2.18x10^-18 J
n = principal quantum number - integers (1, infinity)
4 scenes of transitions of the hydrogen atom from higher energy levels to lower energy levels
E (n=1) - Lymdn
E(n=2)- balmer
E(n=3)- paschen
E(n=4)- bracket
wavelength can’t be _____
Negative
Why is energy quantinized?
De broglie (1924) reasoned that electron is both particle and wave
h/mu
Schrodinger wave equation
An equation that described both the particle and wave nature of the electron
Schrodingers equation can only be exactly solved for ___ atoms. An approximate solution is used for multi electron systems.
Hydrogen
Wave function:
1.
2.
- Energy of electrons with a given wave function
2. (Wave function (sigh))^2 is the probability of finding electrons in a volume of space
Sigh is a function of 4 numbers called _____
Quantum numbers (n, l, m, ms)
m sub s
Quantum number n =
Distance of electron from the nucleus
90% of the electron density is found for the___
1s orbital
Quantum number l=
Angular momentum quantum number
** l=n-1
When n= 1
n=2
n=3
L=?
l= 0
l= 0 or 1
l=0,1 or 2
l=0
l=1
l=2
l=3
What orbital?
0 = s orbital 1= p orbital 2= d orbital 3= f orbital
L represents ….
Shape of the volume of space that the electron occupies
Pauli exclusion principle
No 2 electrons in an atom can have the same 4 quantum numbers
Electrons with the same value of n
She’ll
Electrons with the same values of n and l
Subshell
Electrons with the same values of n l and ml
Orbital
How many electrons can an orbital hold?
2 electron (with opposite spin)
“Fill up” electrons in lowest energy orbitals
Aufbau Principle
The most stable arrangement of electrons in Subshell is the one with the greatest number of parallel spins
Hund’s rule
What are the possible quantum numbers for the last (outermost) electron in Cl?
N=3
L=1
Ml=-1,0,1
Ms= 1/2, -1/2
What is the electron configuration of Mg?
1s^2 2s^2 2p^6 3s^2
Abbreviation: [Ne] 3s^2
Unpaired electrons
Paramagnetic
All electrons paired
Diamagnetic
The distance between identical points on successive waves
Wavelength (lamda)
