2. A period is a row of elements
Properties change gradually and predictably.
3. There are 18 columns of elements
Each column contains a group, or family, of
elements.
A group contains elements that have similar
physical or chemical properties.
4. Divided into sections
Groups 1,2 and the elements in Groups 13-
18
Include metals, metalloids, and nonmetals
5. Groups 3-12
All metals
Inner transition elements are placed below
the main table. (Lanthanide and Actinide)
Why are they called that?
6. All metals are solids
Most with high melting points
Exception is mercury
Has luster (ability to reflect light)
Good conductor of heat and electricity
Malleable (can be pressed into thin sheets)
Ductile (can be drawn out into wires)
Tend to lose electrons and form positive ions in
chemical reactions.
7. Gases or brittle solids at room temperature
Poor conductors of heat and electricity
17
Include many essential for life
› Carbon --phosphorus
› Sulfur --iodine
› Nitrogen
› Oxygen
Tend to gain electrons and form negative ions in
chemical reactions.
8. Nonmetal
Depending on the element with which
hydrogen is reacting, hydrogen will form a
positive or a negative ion.
When bonding with other nonmetals,
hydrogen forms a positive ion.
When bonding with metals, hydrogen forms
a negative ion.
9. An element that shares some properties with
metals and some with nonmetals.
Also called semimetals
10. The box
Name of the element
Atomic number
Symbol
Average atomic mass
Naturally occurring elements include a logo that
tells solid, liquid, gas at room temp.
All gases, except hydrogen, are on the right
side of table
11. Elements that do not occur naturally have a
bulls eye. They are the synthetic elements.
12. One letter or two letter
Based on element name
Sometimes symbols don’t match the names. In
those cases, symbols might come from Greek
and Latin names for elements
Some are named for geographic locations
New elements given a temporary name and
three letter symbol that relates to the atomic
number.