Elements and the Periodic Table
 The Periodic Table is an organized chart of
all of the elements in the entire
universe
For example:
 Iron (Fe) is an element that is found on Earth. The Iron on earth is
identical to the iron atoms found on meteorites.
 The iron atoms on Mars that make the soil red are the same too.
Elements and the Periodic Table
 Elements are the building blocks of all matter
 Elements are the simplest substance in the entire universe. Elements cannot
be broken down into other substances by chemical or physical means (except
by nuclear means)
 - Some examples of elements are: Gold (Au), Oxygen (O),
Copper (Cu), Calcium (Ca), Iodine (I), Chlorine (Cl), and Neon
(Ne)
 Each element has certain properties which distinguishes it
from other elements
 - These properties are: boiling point & melting point, atomic
mass, atomic number, etc.
Organization
of the
Periodic Table
 ˚ The periodic table is organized into horizontal rows and
vertical columns
 The horizontal rows are called periods.
 The vertical columns are called groups.
 There are 7 periods and 18 groups in the periodic table
 Groups are numbered 1-18. These numbers refer to the
number of electrons in the outer shell of the elements.
 (This works for the first 20 elements)
Reading
the
Periodic Table
 Each square on the periodic table give particular
information about the atoms of an element:
- The number at the top of the square is the atomic number, which
is the number of protons in the nucleus of the element
- The element symbol is an abbreviation for the element name
(usually 1-2 letters)
- The element name is below the symbol
- The number below the element symbol is the atomic mass. This
is the mass of all of the isotopes of the element.

Much information can be derived about an element’s atomic
structure just from the information provided in it’s element box.
atomic number = number of protons

atomic mass number= the total number of protons and neutrons

To find the number of neutrons, you take the atomic number
and subtract the atomic mass number
number of neutrons= atomic number - atomic mass number

The number of protons is equal to the number of electrons
number of protons= number of electrons
Reading
the
Periodic Table
 Metals on the left side of the periodic table and
nonmetals on the right side.

-The zigzag line on the right side of the table
separates metals from nonmetals. Elements touching
the zigzag line are called metalloids (except
Aluminum which is a metal)
 Notice: The black bolded elements are solid, the red
letters are a gas and there are 5 liquids on the
periodic table
Categories
of the
Periodic Table
Metals
(general)
-Hard and shiny
- 3 or less valence electrons
- Form positive ions by losing electrons
-Good conductors of heat and electricity
Metals – (specific)
*Reactive metals (alkali and alkaline earth metals)-Alkali metals- very reactive and are found in the
earth’s
crust. Group 1 or 1A
-Alkaline earth metals- soft and malleable & ductile (
bendable
and can be reshaped). Group 2 or 2A
*Transition metals (includes poor metals)-Groups 3-12 (or 3B-2B)
-less reactive than most metals
-found in foods we eat, for industry (steel, copper), modern
technology catalytic converters, and incandescent light bulbs),
and alloys (steel and brass).
*Rare earth metals (lanthanide series and actinide series)-Bottom of periodic table
-previously believed to be rare, however as mining improved,
scientist realized that they are not rare, just hard to isolate.
NonMetals
-Gases or dull, brittle solids
-Do not reflect light
-Cannot be rolled into wires or pounded into sheets
-At room temperature, they can be solids or gases, except
Bromine, which is a liquid.
-5 or more valence electrons
-From negative ions by gaining electrons
-Poor conductors of heat and electricity
*Noble gases- Group 18, almost never react with other elements
-Some are used to make colorful lights
*Halogens- Group 17, very reactive nonmetals that form salts
when combined with many metals.
-Uses: to kill harmful microorganisms in hospitals, to purify
drinking water and prevent growth of algae in swimming
pools.
Metalloids
-Appearance will vary
- 3 to 7 valence electrons
-Form positive and/or negative ions
-Conduct better than nonmetals but nor as well as metals
-Properties of metals and nonmetals
-Often used in semi-conductors for computer chips
NOTE: any element above 92 is too unstable to occur in nature
and must be done in a lab, scientist were able to predict existence
of elements (neon and germaniuim before they were even
discovered
•Groups 1A-VIIIA (1,2 and 13-18) are called the REPRESENTATIVE
ELEMENTS
 Classwork: color code the given periodic table.
Represent the following:
 Alkali metals
 Alkaline-earth metals
 Transition metals
 Rare earths
 Noble gases
 Halogens
 Metals, nonmetals, metalloids