Atomic Structure Flashcards
e
1.6 x 10^-19 C
Atomic number
at the top
Equal to number of protons found in an element
Mass number
Lower number
Sum of protons and neutrons
Isotopes
Atoms that share an atomic number but have different mass numbers/numbers of neutrons
High vs lower electron shells
further higher energy vs closer lower energy
Sharing or transferring valence electrons
Can increase elements stability by filling their highest energy level
Atomic weight
Weighted average of different isotopes
Avogadro’s number
6.022 x 10^23
Planck’s relations (energy of a quanta)
E = hf
h= 6.626 x 10^-34 Js
Bohr’s law of energy of the electron
E = -R(H)/(n^2)
R(H) Rydberg 2.18 x 10^-18 J/electron
Ground state
n = 1
Excited state
e- promoted to a higher orbit/moved to a sub shell of higher than normal energy
Formulas to determine the electromagnetic energy emitted in the form of a photon when electron returns to ground state
E = hc/wavelength
c = 3 x 10^8 m/s
E = hf
E = R(H) x [ 1/(ni^2) - 1/(nf^2) ]
emission spectrum
Love nf = 1 (122, 103, 97, 95, 94)
Big nf = 2 (660, 490, 430, 410)
Penis nf = 3 (1900, 1300, 1100)
1 R(H) is equal to…
13.6 eV/electron
Heisenberg Uncertainty Principle
It is impossible to simultaneously determine with perfect accuracy, the momentum and the position of an electron
Pauli exclusion principle
No two electrons in a given atom can possess the same set of four quantum numbers
Energy state
The position and energy of an electron described by its quantum numbers
n
Principal quantum number
Can take on any positive integer value
The larger the n the higher the energy level and radius of the electron’s shell
maximum number of electrons within a shell
2n^2
Difference in energy between two shells
[1/(ni^2)] - [1/(nf^2)]
l
azimuthal quantum number
Describes shape and # of subshells within a given principal energy level
range: 0 to (n-1)
l=0 is called s (circle)
l=1 is called p (dumbbell)
l=2 is called d
l=3 is called f
maximum number of electrons within a subshell
4l + 2
ml
Magnetic quantum number
Specifies the orbital within a subshell where an electron is most likely to be found at a given moment in time
range: -l ~ +l
How can p subshells be oriented?
x, y, and z
number of orbitals in a subshell
2l + 1
ms
spin quantum number
+1/2 or -1/2
- when two electrons are in the same orbital, they must have opposite spins (paired)
- electrons in different orbitals with the same ms values are said to have parallel spins
Aufbau principle
each subshell will begin filling up before beginning to enter the next one
n+l rule: the lower the sum of n and l the lower the energy of the subshells, if two subshells posses the same sum then the one with the lower n has a lower energy and will fill w electrons first
Hund’s rule
Take up solo spots in the orbitals within a subshell until they NEED to double up
What are the exceptions to Hund’s Rule?
chromium’s group and copper’s group
you move an s electron to the d subshell to make it half full or full
Paramagnetism
materials composed of atoms with unpaired electrons will orient their spins in alignment with a magnetic field
Diamagnetism
Materials consisting of atoms that have only paired electrons will be slightly repelled by a magnetic field
Cation electron loss rule
electrons lost come from highest energy shell (n+l rule)
