Chapter 1: Atomic Structure Flashcards
Do electrons closer to the nucleus have higher energy, or farther?
Farther electrons have higher energies
What is the atomic number?
- Z
- Number of protons
- Bottom number
What is the mass number?
- A
- Sum of an element’s protons and neutrons
- Top number
What is the atomic mass?
Essentially equal (slightly less) to the mass number
What is atomic weight?
- Weighted average of the naturally occurring isotopes in an element
- Periodic table lists atomic weight
How does n influence the energy of an electron?
As n increases, the energy values approach zero from a more negative value
“As electrons go from a lower energy level to a higher energy level, they get AHED”: what does this mean?
- Absorb light
- Higher potential
- Excited
- Distant (from the nucleus)
According to Planck’s equation, what is a positive E? What is a negative E?
- Positive: Emission (jumping to a lower energy level)
- Negative: Absorption (jumping to a higher energy level)
What is an orbital?
Region of space around a nucleus defined by the probability of finding an electron in that region of space
What is the Heisenberg uncertainty principle?
It is impossible to know both an electron’s position and its momentum exactly at the same time.
What is the principle quantum number?
- n
- Describes the average energy of the shell
What is the azimuthal quantum number?
- l
- Describes the subshell within a given principle energy level
- Shape of the orbital
For any given value of n, what is the range of possible values of l?
0 to (n-1)
What is the maximum number of electrons within a subshell?
4l + 2
What is the l value of the s, p, d, and f orbitals?
- s: 0
- p: 1
- d: 2
- f: 3
What is the magnetic quantum number?
- Specifies the particular orbital within a subshell where an electron is likely to be found at a given moment in time
- Orientation
For any given value of l, what are the possible values of ml?
- l to + l
What is the maximum number of electrons within a shell?
2n^2
What is the number of orbitals?
n^2
What is the spin quantum number?
- Indicates the spin orientation of an electron in an orbital
- +1/2 = up
- -1/2 = down
What does the Pauli exclusion principle state?
No two electrons in a given atom can possess the same set of four quantum numbers.
What is the 4f subshell?
- Lanthanide series
- 14 elements
What happens when you are in the d subshell in the periodic table?
- You must subtract n-1, which becomes the number preceding d
- Example: when n = 4, it is 3d, and not 4d
What is Hund’s rule?
Subshells with multiple orbitals (p, d, and f) fill electrons so that every orbital in a subshell gets one electron before any of them get a second.
What does paramagnetic mean?
- Unpaired electrons that align with magnetic fields
- Attracting the material to a magnet.
What dos diamagnetic mean?
- All paired electrons
- Cannot easily be realigned; they are repelled by magnets.
What is the actual configuration of chromium?
(Ar)4s1 3d5
What is the actual configuration of copper?
(Ar) 4s1 3d10
Where are valence electrons found for representative elements?
s and/or p-orbitals
Where are valence electrons found for transition elements?
s and either d- or f-orbitals
What is the Aufbau principle?
Electrons fill from lower- to higher-energy subshells, and each subshell will fill completely before electrons begin to enter the next one.
Which equation allows you to tell which subshell would fill first?
o The lower the sum of the values of n + l, the lower the energy of the subshell, which would fill first.
o If two subshells possess the same n + l value, the subshell with the lower n value fills first.
