CHM-2-Electronic Structure & Periodic Table Flashcards
What are the charges of an:
Electron
Proton
Neutron
-1
+1
0
Ionisation of an atom will make it become an…
Ion - Either a Cation (Positive) or anion (Negative)
What are valence electrons? (3 Points)
The electrons furthest from the nucleus of an atom
- Responisble for chemical properties
- Instrumental in chemical bonding
What is an isotope? (2 Points)
An element with an unequal number of neutrons to the proton number.
Same atomic number but different atomic mass.
What is the ‘dual nature of matter’?
The theory that electrons and subatomic particles are waves as well as particles.
What is the Schrödinger equation?
Describes atomic orbitals as complicated wave functions.
What are quantum numbers used for?
To describe the theoretical position and therefore energy of an electron.
What are the four quantum numbers?
n
ℓ
m\/ℓ
m\/s
Quantum number n (3 Points)
The principle quantum number which determines the radial distribution.
-Integer values 1, 2, 3, 4, 5 etc. represent the shell number and orbital size.
-Higher the value of n, the higher the energy
E.g n=1, n=2, n=3
Quantum number - ℓ
The Angular Momentum (Azimuthal) quantum number
-Defines the atomic orbital shape
-Takes all integer values between 0 and n -1
E.g n=4 Therefore ℓ=0/1/2/3 (Not 4)
Quantum number - m\/ℓ
The Magnetic Quantum Number
- Defines orientation of an orbital
- Can have a value of -1, 0 or 1
Quantum number - m\/s
The Spin Quantum Number
- Simply represents the rotational direction of an electron.
- Can have a value of +1/2 or -1/2 (Antiparalell Spins)
What shape are orbitals with ℓ = 0?
s-shaped (Sperical) - Angular distribution that is uniform at every angle
What shape are orbitals with ℓ = 1?
p-shaped (2 lobes / Dumbell Shaped)
What shape are orbitals with ℓ = 2?
d-shaped (4-leafed Clover shaped)
What shape are orbitals with ℓ = 3?
f-shaped
What shape are p orbitals?
2 lobes / ‘Dumbell’
What comes after f-shaped orbitals?
g, h, I, j etc.
What is heisenberg’s uncertainty principle?
You cannot know the exact position and speed of an object E.g An electron in orbit.
When do values of ℓ = 4 and above occur?
When n ≥ 4.
What is Pauli’s exclusion principle?
No two electrons in an atom can have the same four quantum numbers.
What is Hund’s rule?
Electrons fill orbitals singly first until all orbitals of the same energy are filled.
What is the ground state of an atom?
When the atom is in it’s lowest overall state of energy.
What occurs when the atom is in it’s ground state?
Electronic configuration - where electrons fill orbitals in a set order.
For a given m\/ℓ, a maximum of … electrons are allowed.
2
“Always fill the lowest energy (ground state) orbitals first”
Aufbau Principle.
How many orbitals do s-shapes p-shapes d-shapes f-shapes have?
1
3
5
7
A paramagnetic material is composed of…
atoms with unpaired electrons.
A paramagnetic material is …….. a magnetic field.
Attracted to
A diamagnetic material is composed of…
atoms with paired electrons
A diamagnetic material is …….. a magnetic field.
Repelled by
What is the strongest form of magnetism?
Ferromagnetic magnetism
The excited state configuration is when…
Electrons are promoted to higher unoccupied/partially occupied orbitals through energy input into the electron.
The ‘n’ value is equal to…
The row or period number on the periodic table.
When an orbital is one electron from being half full or full, what occurs?
An electron from the lower subshel jumps to make the next subshell more stable.
In metal ions, transition energies from d-electrons can casue…
coloured solutions
What is the first Ionisation energy/potenital (IE/IP)?
The energy required to remove one of the outermost valence electrons from an atom in it’s gaseous state.
First IE/IP increases as…
You move from left to right accross a period
You move from the bottom to the top of a group
What is the second ionisation energy/potential (IE/IP)
The energy required to remove a second valence electron from the ion to form a divalent ion.
What is electron affinity (EA)?
The energy change that acompanied the following process: X(g) + 1e- ->X-(g)
(X is a given element)
What can the electron affinity be used to measure?
The ability of an atom to accept an electron - The stronger the attraction of a nucleus, the greater the electron affinity.
Why do halogen atoms have a very negative EA?
Because they have a great tendancy to form negative ions.
Element’s EA become more negative as…
You move from left to right on the periodic table
Do not change going down columns
From left to right, the atomic radius of elements
Decrease
What is Electronegativity?
Parameter that measures the atom’s ability to pull or repel bond electrons.
What is determined to achieve the electronegativity value?
1st IE and the EA
The greater the value of electronegativity…
the greater it’s attraction for bonding electrons
The larger the atom…
Electronegativity
The less ability for it to attract electrons for itself in chemical bonding.
The lower the difference between electronegativity in two covalently bonded atoms…
The stronger the bond.
-Due to the bond being shared more equally and thus being more stable.
Why are metals good conductors?
Their valence electrons can move freely
Nonmetals have higher….
Electronegativity and ionisation energies
General characteristics of Metals
Hard/Shiny
3 or less valency electrons
Form + ions by losing e-
Good conductors
General characteristrics of Metalloids
Varied appearejce
3-7 valence electrons
form + and - ions
General characteristics of Nonmetals
Gases/Brittle, dull solids
5+ valence electrons
Form - ions by gaining e-
Group IA
Alkali Metals
Group IIA
Alkaline Earth Metals
Group VIIA
Halogens
Group 0
Noble gases
Which groups are the transition elements?
IB to VIIIB
