1. Introduction to the Periodic Table

2. Dmitri Mendeleev The elements were first arranged in
the periodic table in 1869 by Dmitri Mendeleev.
By arranging all of the 63 elements then known by their atomic weights, he managed to organize them into groups possessing similar properties. Where a gap existed in the table, he predicted a new element would one day be found and deduced its properties.

3. Periods Periods are horizontal rows.
There are 7 periods in the periodic table.

4. Groups Groups are vertical columns.
There are 18 groups in the periodic table.

5. Groups (cont.) The groups can also be labeled 1A – 8A
This helps us to determine valence electrons.

6. Metals

7. Physical Properties of Metals
Conduct heat & electricity
Malleable
Ductile
Lustrous
Almost all metals are solid at normal temperatures. The exception is Mercury, Hg, which is liquid at room temperature.

8. Nonmetals

9. Physical Properties of Nonmetals
Brittle
Not lustrous
Poor conductors of heat &
electricity
Many nonmetals are gaseous
at normal temperatures (N, O, Cl, Ne)
One nonmetal is liquid at normal temperatures (Br)
Several nonmetals are solid at normal temperatures (C, P, S)

10. Metalloids or semimetals

11. Physical Properties of Metalloids
They have an intermediate level of conductivity and thus they make good semiconductors
Show a mixture of metallic & nonmetallic properties
Shiny or dull
Ductile
Brittle

12. Alkali metals

13. Alkali metals Silvery colored
They are soft, and can be easily cut with a knife to expose a shiny surface which dulls on oxidation.
Highly reactive
Low melting temperatures
Low boiling temperatures
Low densities

14. Alkaline earth metals

15. Alkaline earth metals
Metals
Silvery-white color
Highly reactive
Shiny

16. Transition metals

17. Transition metals Lustrous metallic appearance
Many of their compounds are colored
Good conductors of heat & electricity
High melting points
High boiling points

18. Halogens

19. Halogens All halogens exist as diatomic molecules
F2, Cl2, Br2, I2
Fluorine (F2) exists as a poisonous pale yellow gas
Chlorine (Cl2) exists as a poisonous pale green gas
Bromine (Br2) exists as a toxic brownish liquid
Iodine (I2) exists as a black shiny solid that when heated forms a violet vapor

20. Noble Gases

21. Noble Gases Noble gases are Inert – which
means that they are unreactive
and do not readily combine with atoms of other elements
All Noble gases exist as monatomic gases
Low melting points
Colorless, odorless, tasteless
Low densities

22. Lanthanides

23. Lanthanides Strong and durable Magnetic
Used to make lasers, sunglasses, and magnets

24. Actinides

25. Actinides
Unstable
Most of these elements are produced by nuclear reactions
Used in nuclear reactors to produce energy
Used in nuclear weapons
Used as a radioactive technique to determine the age of fossils