1. Organized by Dmitri Mendeleev in 1871
THE PERIODIC TABLE
Organized by Dmitri Mendeleev in 1871

2. A row on the table is called a PERIOD.
PERIODS
A row on the table is called a PERIOD.
The boxes lie in order of increasing atomic number (# of protons) as you move from left to right.

3. TRENDS AMONG PERIODS
Atomic mass generally increases from left to right.
Metallic character decreases from left to right.
Electrons are added one at a time as you move from left to right on the table.
Elements in periods have different chemical properties.

4. GROUPS OR FAMILIES Each column is called a GROUP or FAMILY.
Atomic mass increases as
You move down a group!
Elements in a group are know
to have the same number of
valence electrons and similar
chemical and physical properties.

5. VALENCE ELECTRONS The number electrons in the outermost shell.
Is the same down a group and increases by one as you move from left to right.

6. LEWIS DOT STRUCTURES

7. ALKALI METALS The ALKALI METALS are the most reactive metals.
Reactivity increases as you move down group 1A, wants to lose an electron.
These metals are soft with low melting points and boiling points.
Density increases down the group.

8. ALKALI EARTH METALS
ALKALI EARTH METALS are in group 2A and are not as reactive as group 1A, but are more reactive than most metals.
These metals are soft, but harder than group 1A metals.
2A melting and boiling points are much higher than 1A, but decrease down a group.
Densities generally increase down the group.

9. REPRESENTATIVE METALS
Alkali Metals and the Alkali Earth Metals make up the REPRESENTATIVE METALS or MAIN-GROUP METALS along with some nonmetals in 3A, 4A and 5A.

10. TRANSITION METALS All transition elements are metals.
Densities increase greatly down a group.
Increase in reactivity down a group.
Transition metal compounds have striking colors.
copper(II) sulfate pentahydrate

11. INNER TRANSITION METALS
LANTHANIDES are silvery and high melting metals. Very difficult to separate.
Used for tinting sunglasses
Adding color to TV screens
ACTINIDES are radioactive.
Silvery
Form highly colored compounds

12. METALS Generally shiny solids at room temperature.
Mercury is the only liquid.
Conduct heat and electricity well.
Are malleable – hammered or shaped under pressure without breaking.
And Ductile - Ductility is the physical property of being capable of sustaining large plastic deformations without fracture (in metals, such as being drawn into a wire).

13. NONMETALS
NONMETALS are located in the upper right quarter of the table.
Not shiny, with low melting points.
Gases or brittle solids at room temperature.
Typically poor conductors of heat and electricity. (Carbon in graphite form is a good conductor but it is a nonmetal)

14. HALOGENS Reactive nonmetals, wants to gain 1 electron.
Melting and Boiling Points increase down the group.
Exist as diatomic molecules.
React with most metals and nonmetals.
Chlorine is the most industrially useful halogen. For example, NaCl.
Density increases down a group.

15. NOBLE GASES
All noble gases have the maximum number of electrons possible in their outer shell (2 for Helium, 8 for all others), making them stable, “inert”.
Very low, if any, reactivity.
Melting and Boiling Points are extremely low.
Density increases as you move down the group.

16. METALLOIDS
Metalloids physical properties are more like that of metals, but chemical reactivity is more like nonmetals.
Many properties are some where in between metals and nonmetals.
Most useful b/c they vary in ability to conduct electricity. This property makes metalloids useful in computers and calculators.

17. PREDICTIONS Just like the weather data…We could predict
where on the periodic table of elements a new
element would be placed, based on it’s atomic
mass and chemical and physical properties.