Bell Work
• How do you think the periodic table is
arranged and list for me ways in which you
think the periodic table used. Or what can it
be used for and why is it important?
Periodic Table
• Objective: How are elements arranged on
the periodic table?
Periodic Table
• In 1869, Russian chemist Dmitri
Mendeleev arranged the elements in order
of increasing atomic mass.
• However, there were gaps in the table.
• In 1914, British scientist Henry Moseley
found the number of protons —the atomic
number.
• When the elements were arranged by
atomic number, they fit the pattern in
Mendeleev’s table..
Periodic Squares
• So the periodic table is arranged by increasing
atomic number.
• Each Element is Identified by a Chemical Symbol.
• Each square on the periodic table includes an
element’s name, chemical symbol, atomic
number, and atomic mass.
• For most elements, the chemical symbol has one
or two letters. The newest elements have
temporary three-letter symbols.
• The 1st letter is always capitalized and the 2nd
letter is always lower case.
Periodic Squares
• Please draw and label the following
periodic square!
Arrangement of the P.T.
• Each horizontal row of elements is called
a period. The chemical and physical
properties of elements in a row follow a
repeating pattern as you move across the
period.
• Each vertical column of elements is called
a group. Elements in the same group often
have similar chemical and physical
properties.
Understanding P.T.
• Elements are classified as metals, nonmetals,
and metalloids, by their properties.
• The number of electrons in the outer energy level
of an atom is one characteristic that helps
determine which category an element belongs in.
• The zigzag line on the periodic table can help you
recognize which elements belong in which
category.
Parts of P.T.
Zig-zag line
Metals
• Metals are found to the left of the
zigzag line. Atoms of most metals
have few electrons in their outer
energy level.
• Most metals are shiny, ductile,
malleable, and are good conductors
of electric current and thermal
energy.
Nonmetals
• Nonmetals are found to the right of the
zigzag line. Atoms of most nonmetals
have an almost complete set of electrons
in their outer energy level.
• Nonmetals are not shiny, ductile, or
malleable, and are poor conductors of
electric current and thermal energy.
Metalloids
• Metalloids are the elements that border
the zigzag line. Atoms of metalloids have
about half of a complete set of electrons in
their outer energy level.
• Metalloids have some properties of metals
and some properties of nonmetals.
Metalloids are also called semiconductors.
Objective
• EXIT TICKET: write on ½ sheet and
answer then give to Ms.Jones on way out!
• What are the location on the periodic table
of metals, nonmetals, and metalloids?
Objective
• On ½ sheet of paper answer the following
question
• List all the major groups of the periodic
table by their names.
Groups of P.T.
• Group 1 - Alkali metals
• Alkali metals are elements in Group 1
of the periodic table.
• Alkali metal properties: - group
contains metals - 1 electron in the
outer level - very reactive - softness,
color of silver, shininess, low density
Group 2 - Alkaline-earth
metals
• Alkaline-earth metals are elements in
Group 2.
• Alkaline-earth metal properties: group contains metals - 2 electrons
in the outer level - very reactive, but
less reactive than alkali metals color of silver, higher densities than
alkali metals
Transition Metals
• Transition metals are in Groups 3–12.
• Properties of Transition Metals vary
widely but include: - groups contains
metals - 1 or 2 electrons in the outer
level - less reactive than alkalineearth metals - shininess, good
conductors of electric current and
thermal energy
Transition Metals
3-12
Group 13 – Boron
• Aluminum is the most common
element from Group 13.
• Group 13 properties: - group
contains 1 metalloid and 5 metals - 3
electrons in the outer level - reactive
- solids at room temperature
Group 14 – Carbon
• Group 14 properties: - group
contains 1 nonmetal, 2 metalloids,
and 2 metals - 4 electrons in the
outer level - reactivity varies among
the elements - solids at room
temperature
Group 15 – Nitrogen
• Group 15 properties: - group
contains 2 nonmetals, 2 metalloids,
and 2 metals - 5 electrons in the
outer level - reactivity varies among
the elements - solids at room
temperature (except for nitrogen,
which is a gas)
Group 16 – Oxygen
• Group 16 properties: - group
contains 3 nonmetals, 1 metalloids,
and 1 metal - 6 electrons in the outer
level - reactive - solids at room
temperature (except for oxygen,
which is a gas)
Group 17 – Halogens
• Group 17 properties: - group
contains nonmetals - 7 electrons in
the outer level very reactive - poor
conductors of electric current, never
in uncombined form in nature
Group 18 – Noble Gas
• Group 18 properties: - group
contains nonmetals - 8 electrons in
the outer level (except helium, which
has 2) - have a full outer shell unreactive - colorless, odorless
gases at room temperature
Hydrogen
• The properties of hydrogen do not
match the properties of any single
group, so hydrogen is set apart: - a
nonmetal - 1 electron in the outer
level - reactive - colorless, odorless
gas at room temperature - low
density