Atomic + Molecular Structure Flashcards
What did Dalton’s Atomic Theory state?
- All elements are composed of atoms
- Atoms of 1 element differ from atoms of other elements
- All compounds of composed of different atoms
- No destruction/construction of atoms
Protons weigh about
1 amu
The atomic # (or Z) equals to the
Number of protons
The further the valence electron is from the nucleus the
Weaker the attraction is between the electron and the nucleus
Rutherford stated that the atom has a
Densely-charged nucleus which accounts for a small portion of the volume
Planck developed the first quantum theory, proposing that
Energy is emitted as electromagnetic radiation in quanta
What is the energy of a quantum?
E = h • f
What is the angular momentum (L) according to the Bohr model?
L = nh / 2π
The energy of the electron is given by
E = -Rh / n^2
The energy of an electron is related to the
Orbital radius
The smaller the radius means the
Lower the energy
What is the electromagnetic energy of protonss?
E = h•c / wavelength
Each element maintains its own
Atomic emission spectrum
The Lyman series describes emission to
n = 1 (UV)
The Balmer series describes emission to
n = 2 (UV + Vis)
The Pascher series describes emission to
n = 3 (Inf)
What is the equation to find energy level transitions?
E = -Rh (1/ni^2 - 1/nf^2)
The pauli exclusion principle states that
No 2 electrons in a given atom have the same 4 quantum numbers
The max number of n correlates to the
Number of the period
The larger the n the
Higher the energy level + radius
The max number of electrons in a SHELL is denoted by
2n^2
As the distance from the nucleus increases, the
Difference in energy between adjacent shells decreases
The azimuthal quantum number (l) ranges from
0 to n-1
When l = 0, the orbital is
S
When l = 1, the orbital is
P
When l = 2, the orbital is
D
When l = 3, the orbital is
F
The maximum number of electrons found in a subshell can be found by
4l + 2
The greater the value of l, the greater the
Energy
The magnetic quantum number (ml) ranges from
l to -l
Two electrons in the same orbital must have
Opposite spins
Electrons in different orbitals with the same ms values have
Parallel spins
Electrons in the same orbitals with different ms values have
Paired spins
The Aufbau principle states that
Subshells are filled from the lowest to highest energy
Which equation allows for one to determine subshell energy?
(n + 1)
The lower the sum of (n+1) the
Lower the energy
Hund’s Rule states that
Orbitals are filled first before pairing
When a molecule is paramagnetic it means that it contains
Unpaired electrons
How does the magnetic field act when an atom is paramagnetic?
It aligns the spin of the electrons and attracts them
Diamagnetic atoms lack
Unpaired electrons
Diamagnetic atoms are repelled by the
Magnetic field
Which atoms are stable?
Ones with half-filled or fully-filled subshells
Half-filled subshells are found in columns
6 and 12
