Download Periodic Table and Reactivity

Periodic Table
Performance Indicator 7.P.2A.2
Essential Questions:
2. How are elements classified on the
periodic table?
Periodic Table
Atom
• The basic unit of a chemical
element. (ex: gold, oxygen,
mercury)
• Consists of 3 basic parts.
(protons, neutrons, electrons)
• The atomic mass is the sum of
the protons and neutrons.
© KeslerScience.com
Periodic Table
Electrons
• Negatively charged
subatomic particle.
• Located outside the
nucleus.
© KeslerScience.com
Periodic Table
Valance Electron
• An electron in one of the
outer shells of an atom that
can participate in forming
chemical bonds with other
atoms.
• The number of valance
electrons determines the
element’s reactivity.
© KeslerScience.com
Periodic Table
Periodic Table
• The periodic table is used
to organize all of the
elements.
• Every periodic table will
have a square for each
element with the element
name, chemical/element
symbol, atomic number,
and atomic mass.
© KeslerScience.com
Quick Action – INB Template
1. Cut out the INB
Template.
2. Complete the blanks
with words from the
following slide.
3. Paste tab in your
notebook.
© KeslerScience.com
14
Si
28.086
Silicon
______________________
______________________
______________________
______________________
______________________
______________________
Periodic Table
What can we tell about this
element (atom) from the periodic
table?
1. The atomic number(14), which is
also the number of protons.
2. The symbol for nitrogen. (Si)
3. The atomic mass. (28.0086)
4. The element’s (atom’s) name.
(Silicon)
© KeslerScience.com
14
Si
28.0086
Silicon
Periodic Table
Chemical/element symbols
oEach element has a different symbol
oSymbols are written with one, two, or three letters.
oThe first letter is always capitalized
oStudents should be familiar with following element
names and symbols:
©
KeslerScience.com
©
KeslerScience.com
Element
Symbol
Element
Symbol
Hydrogen
Carbon
Nitrogen
Oxygen
Chlorine
Magnesiu
m
Zinc
Calcium
Phosphorus
H
C
N
O
Cl
Mg
Silicon
Copper
Aluminum
Silver
Gold
Iron
Si
Cu
Al
Ag
Au
Fe
Zn
Ca
P
Helium
He
Potassium K
Sodium
Na
Periodic Table
Atomic Number
• The atomic number of an element is equal to the
number of protons.
• The atomic number is a whole number
• The atomic number is always the same for a given
element.
• The elements on the periodic table are arranged
numerically by increasing atomic number.
©
KeslerScience.com
Periodic Table
Atomic Mass
• The atomic mass is an average sum of the number
of the protons and the number of neutrons in the
nucleus of the atom.
• Since the atomic mass of an element is an average,
it is usually not a whole number.
©
KeslerScience.com
Periodic Table
Periods
• A horizontal row on the periodic table is called a
period.
©
KeslerScience.com
Periodic Table
Families
• Families, also called groups, are vertical columns of
elements on the periodic table
• They are numbered 1-18
• Elements in the same family have similar properties
©
KeslerScience.com
Metals, Nonmetals and Metalloids
Periodic Table Classification:
Metalloids (green)
• There is a zigzag line on the
right side of the periodic
table that separates the
metals from the nonmetals.
Metalloids are found along
this zigzag line.
• Elements identified as
metalloids have properties
(characteristics of both
metals and nonmetals
© KeslerScience.com
Metals, Nonmetals & Metalloids
Periodic Table
Periodic Table Classification:
Metals (blue) properties:
• Metals are generally
located on the left side
of the zigzag line.
• Examples of metals are:
Sodium (Na), Calcium
(Ca), Iron (Fe), and
Aluminum (Al).
• The majority of elements
are metals.
© KeslerScience.com
Metals, Nonmetals & Metalloids
Periodic Table and Reactivity
Periodic Table Classification:
Nonmetals (red) properties:
• Nonmetals with the exception of
Hydrogen (H), are located on the
right side of the zigzag line on the
periodic table.
• Examples of nonmetals are:
Chlorine (Cl), Oxygen (O), Sulfur (S),
and Iodine (I).
© KeslerScience.com
Metals, Nonmetals & Metalloids
Quick Action – Match the words with the
definition
With a partner match the classification with the object.
1.
Metal
2.
Nonmetal
3.
Metalloid
© KeslerScience.com
A.
B.
C.
D.
E.
Shiny new Yeti cup
Carbon in your pencil lead
Yellow glob of sulfur
Nitrogen in the air
Silicon used in microprocessors
in cell phones
F. Helium in a balloon
G. An aluminum can
STOP
©
KeslerScience.com
Quick Action – INB Template
Periodic Table INB - Let’s add some more information to your periodic
table on the upcoming slides.
© KeslerScience.com
Quick Action – INB Template
Trends on the Periodic Table
2
• Elements in Period 3 have 3 orbitals
• Elements in Period 7 have 7 orbitals
• Moving down the Period increases the
reactivity
• Cs is more reactive than K
• Li is less reactive than Na
• Draw a down arrow next Period 1-7
and put the words “increasing energy
and reactivity.”
© KeslerScience.com
Increasing energy and reactivity
• Moving down the Period (Rows 1-7)
the number of energy levels or shells
increases by 1.
1
Quick Action – INB Template
• IA Group has one valance
electron.
• 5A Group has five valance
electrons.
• Copy the notes and orange
arrow.
© KeslerScience.com
2
Increasing energy and reactivity
Trends on the Periodic Table
• Groups (Columns 1-18) –
elements have the same
number of valance electrons
in each group.
• Valance electrons are the
electrons in the outer energy
level (shell).
Same# of valance
electrons going
down the column
1
Quick Action – INB Template
Trends on the Periodic Table
• Reactivity increases as you
move from right to left across
the periodic table.
Same# of valance
electrons going
down the column
1
Increasing energy and reactivity
• Draw an arrow indicating
“increasing reactivity.”
2
Increasing reactivity
© KeslerScience.com
Periodic Table and Reactivity
Reactivity of atoms
• The ability of atoms to
combine or separate with
other atoms to create new
substances (chemical
reaction)
• Valance electrons are the key
to this process.
• Reactivity changes across the
periodic table.
© KeslerScience.com
Quick Action – Group PT Model
1. Assign four students to each be a different
atom from Period 2.
2. Have the four students come up in front of the
class and “act out” their level of reactivity
based on their position on the periodic table.
3. Notice the differences in their reactivity and
how it relates to the periodic table.
© KeslerScience.com
Periodic Table and Reactivity
What makes an atom “happy”
(stable)
• Having its outer energy level (shell)
filled with electrons.
• Example: (8A) highlighted in red.
• These atoms do not want to bond
with other atoms. (inert)
• Helium is the exception because it is
“happy” (stable) with only two
valence electrons.
© KeslerScience.com
8A
Periodic Table and Reactivity
What happens if an atom doesn’t
have 8 valence electrons?
• Hydrogen has only one valance
electron. (Group 1A).
• Does not follow the rule of 8, but
its “happy” number is 2.
Who might hydrogen bond with
to make itself “happy (stable)?”
© KeslerScience.com
Hydrogen
Periodic Table and Reactivity
Hydrogen easily bonds with
itself!
This way both hydrogen
atoms can share an electron
and be “happy (stable).”
© KeslerScience.com
Hydrogen
Hydrogen
Periodic Table and Reactivity
Let’s look at oxygen?
Oxygen has six valence electrons
(It’s in Groups 6A.)
It needs to bond with one atom
that either has two valance
electrons, or two atoms that have
one valance electron.
© KeslerScience.com
Oxygen
Periodic Table and Reactivity
• Now oxygen is “happy”
(stable).
Hydrogen
Hydrogen
• It bonded with 2 hydrogen
atoms making a molecule of
H20 (water).
• Sometimes called the Mickey
Mouse Molecule.
Oxygen
© KeslerScience.com
Check for Understanding
Can you…
1. Identify that valence electrons determine
an atom’s chemical properties, including
reactivity.
2. Interpret the arrangement of the periodic
table to explain how properties are used
to classify elements, including periods and
groups.
© KeslerScience.com