Periodic Trends Notes
Periodic Trends Notes
• The periodic table
organizes all
known elements
according to their
number of protons.
• The unique shape
of the table reveals
the ways in which
the electrons are
organized around
the atom in energy
levels.
Periodic Trends Notes
• The structure of an element (especially the
number of protons and the number of electrons)
will determine the properties of the element (how
it will appear, how it will act, etc.)
• The periodic table can be broken into regions
where all the elements in a region have very
similar properties. These regions (and
subregions) are commonly given names:
Periodic Trends Notes
• 1. The largest region is the
Metals. On page 77, everything
in blue is a metal, and they all
have certain characteristics in
common. They conduct heat and
electricity very easily, they are
lustrous (shiny) and malleable
(can be bent, flattened, etc).
Periodic Trends Notes
• 2. The second largest region is the Nonmetals. These elements (red on page 77) are
generally poor conductors of heat and
electricity, and when solid are brittle (can be
broken or shattered).
Periodic Trends Notes
• 3. Another region is
the Metalloids. These
elements (yellow on
page 77) have
characteristics of
metals and nonmetals, which vary
with the element.
(above: selenium, below: silicon)
Periodic Trends Notes
• 4. Noble gases are located
on the far right (green on
page 77) and rarely (some
never) react with other
elements in chemical
reactions.
• This is because they have
enough electrons to fill up
the p orbital, which makes
them very stable.
Periodic Trends Notes
• **Octet Rule**--This rule states that atoms
will be more stable if they have a filled s
and p orbitals for their outermost electrons
(called valence electrons). Many elements
will either lose or gain electrons from other
atoms in order to achieve this full “octet”
(outermost 8 electrons).
Periodic Trends Notes
• Rows on the periodic table (horizontal) are
called periods. The number of the period will
correspond with the energy level of the
outermost electron.
Periodic Trends Notes
• The periodic table can also be broken up into subregions called groups. Each column (up/down) is a
group, so the far left column is known as group 1, and
the far right column (noble gases) is called group 18.
Periodic Trends Notes
• Typically groups that are next to each
other will have similar chemical properties,
and the further away two groups are the
more different they will be.
Periodic Trends Notes
• Some groups have
names:
1. Group 1 is called the
Alkali Metals. They are
soft and highly reactive.
This is because they
have a single electron in
their s orbital, which can
be lost very easily in
chemical reactions, which
will make them more
stable.
Periodic Trends Notes
• 2. Group 2 is called the
Alkaline-Earth Metals. They are
less reactive than Alkali Metals
because they have two
electrons in the s orbital, which
is more difficult to lose in order
to be stable. They are also
harder and more dense
(therefore strong). However,
they are still very reactive.
Periodic Trends Notes
• 3. Groups 3-12 are called Transition
Metals. They widely vary in chemical
properties. Among the transition metals
are the two rows on the very bottom (f
orbitals). The first row is called the
Lanthanides, and the second row is called
the Actinides.
Periodic Trends Notes
• 4. Group 17 is called
the Halogens. These
are the most reactive
non-metals, because
they need only one
electron to fill their
octet.
Periodic Trends Notes
• 5. Hydrogen is
the only element
that composes
its own region of
the periodic
table.
Region/Group Review
What group or region of the Periodic Table are the following
elements found in?
1. Strontium (Sr, #38)
2. Tantalum (Ta, #73)
3. Curium (Cm, #96)
4. Antimony (Sb, #51)
5. Sulfur (S, #16)
1. Alkaline Earth Metal, 2. Transition Metal,
3. Actinides (Transition Metal) 4. Metalloid,
5. Non-Metal
•
1.
2.
3.
4.
5.
What physical appearance do they
have?
Strontium (Sr, #38)
Tantalum (Ta, #73)
Curium (Cm, #96)
Antimony (Sb, #51)
Sulfur (S, #16)
More Review
Strontium (Sr, #38)
1. Tantalum (Ta, #73)
• Curium (Cm, #96)
• Antimony (Sb, #51)
• Sulfur (S, #16)
• What will they do with their electrons in a
chemical reaction?
1.Strontium (Sr, #38)
2.Tantalum (Ta, #73)
3.Curium (Cm, #96)
4.Antimony (Sb, #51)
5.Sulfur (S, #16)
1.
2.
3.
4.
5.
Strontium (Sr, #38)—lose two electrons
Tantalum (Ta, #73)—unpredictable
Curium (Cm, #96)—unpredictable
Antimony (Sb, #51)—gain 3 electrons
Sulfur (S, #16)—gain 2 electrons