Periodic Table of Elements
Sorting the elements
Dmitri Mendeleev
• Created the periodic table to
account for the regular properties of
elements
• Proved to be very powerful by also
predicting the existence of several
new elements: gallium, geranium,
and scandium.
What is the periodic table?
• It is a list of all known elements organized into a table
• The elements are placed on the table based on the number of
protons in their nucleus
• All the elements in a column share similar chemical properties
Periodic Table organization
Increasing
number of
protons
(bigger
atoms)
Periodic Table organization (cont.)
Each column in the periodic table shares some
chemical properties. Chemists have names for
each column.
Periodic Table organization
Each new row indicates another “orbital” or “layer” of
electrons being filled.
Orbitals
Periodic Table organization (cont.)
Gaps are to make the table fit the largest “orbitals”
(basically to make the table look better)
Reading the information from an element
• Every box in the periodic table represents an element and has 4 parts
to it
1. Name
1. Name: What we call the element.
2. Atomic
number
2. Atomic number: The number of protons in the
nucleus.
3. Symbol
3. Symbol: The one- or two-letter “short name” for
the element.
4. Atomic
mass
4. Atomic mass: How heavy the element is on
average. Mass of protons + neutrons.
Look at the periodic table and find out what
your element was!