Unit 1 exam 2
Shielding
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For electrons in n = 1 there is no shielding. Only one shell
For electrons in n = 2 there is shielding, 2 electrons are shielding the
valence electrons
For electrons in n = 3 there is shielding, 10 electrons are shielding the
valence electrons
Calculate the number of electrons that are
shielded by
An electron in n=1 for Li
An electron in n=2 for Li
Calculate the Effective nuclear charge for…
An electron in n=1 for Li
An electron in n=2 for Li
Zeff:
Zeff:
Complete the electron configurations below
Atom: Mg2+
Atom: P3-
Long notation:
Long notation:
Short notation:
Short notation:
Isoelectronic series:
Isoelectronic series:
The more unpaired the more
magnetic
Give an example of a paramagnetic atom
Element:
Magnetic: Yes or No
Electron configuration:
Orbital notation:
Give an example of a diamagnetic atom
Element:
Magnetic: Yes or No
Electron configuration:
Orbital notation:
Order of electron configurations
If the order isn’t
followed aufbau
principle is not being
followed
Lowest
energy
highest
energy
Write out the atomic orbitals in order of
decreasing energy
Write out the atomic orbitals in order of
increasing energy
Electronegativity
Electronegativity refers to the
ability of an atom to attract shared
electrons in a covalent bond. The
higher the value of the
electronegativity, the more strongly
that element attracts the shared
electrons.
Rank O, S, Cs, and Ba in the order of
decreasing EN
What is the EN difference between
Hydrogen and Flourine
Atomic Radius
distance from the
center of the
nucleus to the
boundary of the
surrounding shells
of electrons.
Rank O, S, Cs, and Ba in the order of decreasing radius.
Ionization energy
the amount of
energy required to
remove an electron
from the gaseous
form of that atom or
ion
Which of the following atoms has the
highest first ionization energy?
A.
B.
C.
D.
Na
K
Sc
Rb
Which of the following atoms has the
lowest first ionization energy?
A.
B.
C.
D.
Na
K
Sc
Rb
Electron Affinity
the degree to which an
atom or molecule
attracts additional
electrons.
Metallic character
How do you identify a metallic
character?
Physical properties associated
with metallic character include
metallic luster, shiny
appearance, high density,
high thermal conductivity,
and high electrical
conductivity
Quantum Review
• Schrodinger developed quantum mechanics. Explains wave
behavior of electrons.
• Can’t know exact location, but we can figure out the most
probable location.
• Not all locations are possible. There are rules for where
electrons are found. These are quantum rules.
The Four Quantum Numbers
n = distance of electrons from nucleus, energy level (the shell number). Size
-
1, 2, 3, 4, 5, 6
1s, 2s, 2p, 3s, 3p, 3d
𝑙 = the shape of the orbit (the subshell)
-
0, 1, 2, 3
s= 0
p= 1
d= 2
f= 3
𝑚𝑙 = orientation of the orbit (the orbital)
-
-3, -2, -1, 0, 1, 2, 3
𝑚s= the spin of the electron
-
+½ or -½.
Subshell (l)
Magnetic quantum number
Magnetic spin
Quantum boundaries
Periodic Table Nomenclature
Periodic table nomenclature
• It lets you calculate molar mass
Know the definitions of:
• It lets you know the numbers of
electrons, protons, and neutrons
Period, group, family, block, main
group, transition metal,
lanthanum, actinium series, alkali
metal, alkali earth metals,
halogens, noble gases, shell,
subshell, orbital, nonmetals,
metals, metalloids.
• It tells you the number of valence
electrons
• It answers quantum rules
• It tells you the energy levels of electronic
configurations
• It tells you the state of element form
Periodic table
Order of electron configurations (aufbau
rule)
If the order isn’t
followed aufbau
principle is not being
followed
Lowest
energy
highest
energy
Hunds rule
Spread them out
Pauli rule
Only 2 per orbital in opposite directions