The Periodic Table of
the Elements
HISTORY
• Created by Dmitri Mendeleev in 1869
• Mendeleev was so confident in his table that he
used it to predict the physical properties of
three elements that were yet unknown.
• Organized in rows and columns
PERIODS
• Period: horizontal
groups
• The elements have the
same number of
atomic shells from 1 to
7 for its electrons
GROUPS
• Groups: vertical
columns
• Elements in the
same group have
similar properties
FAMILIES
• Elements are
grouped together
based on their
properties
chlorine
nitrogen
gold
silver
mercury
oxygen
hydrogen
helium
sodium
niobium
neodymium
carbon
Elements
• Science has come
along way since
Aristotle’s theory of Air,
Water, Fire, and Earth.
• Scientists have
identified 90 naturally
occurring elements,
and created about 28
others.
Elements
• Element: any of
more than 100
known substances
that cannot be
separated into
simpler substances
• The elements make
up our world, our
sun, and in fact, the
entire universe
The most abundant element in
the earth’s crust is oxygen.
3 Categories of the
Periodic Table
1. Metals
2. Non-metals
3. Metalloids
3 Categories of the
Periodic Table
1. Metals:
• Good conductors of heat
and electricity
• Shiny, ductile, malleable
• Reacts with water which
results in corrosion
• Almost 75% of all
elements are classified
as metals
3 Categories of the
Periodic Table
2. Non-Metals:
• Poor conductors of
heat and electricity.
• Brittle and break
easily, dull
• Many non-metals
are gases.
Flourine (Fl), Chlorine (Cl),
Bromine (Br), Iodine (I),
Astatine (At)
3 Categories of the
Periodic Table
3. Metalloids/Semimetals: (metal-like)
have properties of
both metals and
non-metals.
• can be shiny or dull.
• ductile and
malleable.
• Uses: computers,
calculators and
electronics
Review
• What is one property of metals?
Review
• What is one property of non-metals?
Review
• What is a metalloid?
Practice Identifying
Based on what you know AND this element’s place in
the periodic table, what category is it? Metal,
nonmetal or metalloid?
1. Oxygen – a gas, doesn’t conduct electricity well
2. Silver – shiny, malleable, conducts heat
3. Hydrogen – gas, first element on the periodic table
Discuss with your group
YOUR PERIODIC TABLE!
Steps:
1. Create a key
2. Label the categories
3. Outline each category
4. Color
Exit Ticket
Answer:
What are the three categories of
elements?
Give ONE element from each category
YOUR PERIODIC TABLE!

Alkali Metals

Alkaline Earth Metals

Transition Metals

The Halogens

The Noble Gases
LANTHANIDES
ACTINIDE
If I Were an Element…
You have been abducted by aliens! They want to make all
the humans into elements to save space. They’re only kind
act is to let you choose what KIND of element you want to
be.
Write a persuasive letter to them about what kind of
element you want to be
Describe the element or category
Make it a good plea! They may be very hard-hearted 
Dear Mr. Alien,
If I were an element, I would like to be…
ALKALI METALS Group I
• AKA as Alkaline
metals
• Very reactive
• Shiny and light
weight
Lithium (Li), Sodium (Na),
Potassium (K), Rubidium (Rb),
Cesium (Cs), Francium (Fr)
ALKALINE-EARTH
METALS
• 2nd most reactive
family
• When in solutions, pH
is greater than 7
• Found in fireworks,
batteries, flashbulbs
• Mg and Ca important
in diet
Beryllium (Be), Magnesium (Mg),
Calcium (Ca), Strontium (Sr), Barium
(Ba), Radium (Ra)
HALOGENS
• They have 7 e- in their
outer shell.
• Easily combine with
other elements often
metals and elements
from Group I.
• Fl is most reactive.
Reactivity
Flourine (Fl), Chlorine (Cl), Bromine
(Br),
Iodine (I), Astatine (At)
NOBLE/INERT GASES
• Group XVIII
• Have full shells of
electrons, so they
don’t react with
other elements
• Become more rare
as they move down
the Table.
Helium (He), Neon (Ne), Argon (Ar),
Krypton (Kr), Xenon (Xe), Radon (Rn)
TRANSITION
METALS
• Difficult to explain
because of their
electron orbital
arrangement
• Can have different
number of electrons
in outer shells
LANTHANIDES
• Inner-transition
metals
• Found naturally on
Earth
ACTINIDES
• All are radioactive
• Not all are found in
nature
• Some are made in
labs.
Review Qs
Pick a Group!
With your group, pick a group:
•Alkali Metals
•Alkali Earth Metals
•Halogens
•Noble Gases
Create an advertisement that highlights characteristics of
the group (the periodic kind, not YOUR group)
Include:
• 2-3 characteristics
• # of valence electrons
• A CATCHY slogan/saying – think marketing!
• Use the handout for more information