PT trends Flashcards
PERIOD
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GROUP
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PERIODIC LAW:
The properties of the chemical elements recur periodically when the elements are arranged from lowest to highest atomic numbers
Alkali Metals:
elements in the 1st column (except H)
Alkaline Earth Metals:
elements in the 2nd
column
Halogens:
elements in the column headed by Flourine
Noble Gases:
elements in the column headed by He
Lanthanides:
elements in the row starting with
Lanthanium
Actinides:
elements in the row starting with actinum
The Properties of Metals:
• Reflect light when polished
• Are opaque
• Good conductors of electricity and heat
• Are generally flexible when in thin sheets
• Are generally malleable (can be hammered into thin
sheets) and ductile (drawn or stretched into wires)
• Usually solid at room temp
The Properties of Non‐metals:
• Are gases, liquids or brittle solids at room temperature
• Are poor heat and electrical conductors
• If solids, are dull to lustrous in appearance and opque to
translucent
The Properties of Metalloids:
• They have properties which resemble metals more
than non‐metals
The important difference between metals and
metalloids:
• Metals: Electrical conductivity DECREASES
with INCREASING temperature
• Metalloids: Electrical conductivity
INCREASES with INCREASING temperature
Metallic Properties: Left to right across the table & reason
• Left to right across the table ‡ metallic properties
decrease
‐ Reason: Moving from the metal side to the non‐metal
side of the PT
Metallic Properties: Down a family
• Down a family ‡ metallic properties increase
Describe Atomic Radius in terms of attraction
• Atomic radius is influenced by the force of
attraction between the positive nucleus and the
negative e‐
• This attraction is the ‘glue that holds the atom
together’
• The larger the charges the greater the forces
Atomic Radius: Down a family & reason
• Down a family ‡ atomic radius increases
‐ Reason: As you move down you increase the number of energy levels
• This means that the e‐ are farther away from the
nucleus
• The greater the distance between the p & e‐ ‡
decreased force of attraction
• Therefore the nucleus can’t hold the e‐ close and the
atomic radius increases
Atomic Radius: Left to right across the table & reason
• Left to right across the table ‡ radius decreases
‐ Reason: you are moving along the same energy level but increasing the # of p and #e
• More p & e = more charge ‡ greater force of attraction
between the p and the e‐
• Therefore the nucleus holds the e‐ closer and the
radius decreases in size
What is Electrical conductivity dependent on? What is electricity?
• Electrical conductivity depends on the atom’s ability
to transfer e‐
• Electricity is the movement of e‐
The better an atom holds on to its e‐:
the less its ability of the atom to transfer e‐ = decreased ability to be a conductor
E. conductivity: The worse an atom hangs on to its e‐: (conductor ability)
the greater the ability of the atom to transfer e‐ = increased ability to be a conductor because electricity is the movement of e-
Electrical conductivity: Increased charge=
more p & e‐:
• Increased force of attraction
• Decreased distance of orbitals ‡ increased
force of attraction
• Increased force of attraction between p & e‐
will increase the hold that the nucleus has on
the e‐ and the decrease the ability for the e‐ to
move
Electrical conductivity: Decreased distance of orbitals=
increased force of attraction
What does Increased force of attraction between p & e‐do?
increase the hold that the nucleus has on
the e‐ and the decrease the ability for the e‐ to
move
Electrical conductivity: Left to right across the PT & reason
• Left to right across the PT ‡ conductivity
decreases
‐ Reason: The nucleus has a strong hold on the e‐because of the decreased atomic radius
• e‐ are less able to move (they are very attracted to
the nucleus)
Electrical conductivity: Down a family on the PT & reason
• Down a family on the PT ‡ conductivity increases
‐ Reason: The nucleus has a lesser hold on the e‐ because of the increased atomic radius
• e‐ are able to move more freely (more distance
between the e‐ and the nucleus)
Relationship between conductivity and
atomic radius:
‐ Large radius ‡ increased conductivity
‐ Small radius‡decreased conductivity
Relationship between conductivity and
metallic characteristics:
‐ Increased conductivity ‡ increased metallic
characteristics
‐ This makes sense because we know that metals are
good conductors
Ionization energy: define
energy required to steal an e‐ from
an atom
• It is based on how well the nucleus can hang onto its
own e‐
Ionization energy: Smaller atomic radius =
greater hold that the atom has on its e‐ = greater the ionization energy
Ionization energy: Larger atomic radius =
lesser hold that the atom has on its e‐ = smaller ionization energy
Ionization energy: Left to right across the PT & reason
• Left to right across the PT ‡ ionization energy increases
‐ Reason: The nucleus has a strong hold on the e‐ because of the decreased atomic radius
• Can hold onto its own e‐ and can also steal other e‐
Ionization energy: Down a family on the PT & reason
• Down a family on the PT ‡ ionization energy decreases
‐ Reason: The nucleus has a lesser hold on the e‐ because of the increased atomic radius
• Cannot hold onto its own e‐ very well therefore won’t be able to steal others’ e‐ either
Electronegativity: define
the ability of a bonded atom to attract shared electrons to itself
Electronegativity: Big radius =
smaller attractive power of the
nucleus = smaller electronegativity
Electronegativity: Left to right across the PT & reason
• Left to right across the PT ‡ electronegativity
increases
‐ Reason: The nucleus has a strong hold on the e‐ because of
the decreased atomic radius = is able to attract e‐
- Small Radius = Large Attractive Power
Electronegativity: Down a family on the PT & reason
• Down a family on the PT ‡ electronegativity decreases
‐ Reason: The nucleus has a lesser hold on the e‐ because of the increased atomic radius = can’t attract other e‐
- • Down a family on the PT ‡ electronegativity decreases
‐ Reason: The nucleus has a lesser hold on the e‐ because of the increased atomic radius = can’t attract other e‐
Do noble gases have the ability to bond with other
atoms?
No
Do noble gases have electronegativity? Why?
No, they don’t bond with other atoms
