1. Periodic Table of Elements

2. What is an element?
Element - a pure substance that cannot be broken down into simpler substances
In other words, made up of only one kind of atom
Elements can be divided into:
Metals
Non-metals
Metalloids

3. Each element has its own symbol
ONLY two letters long (normally)
Starts with a capital and ends with a lowercase

4. Dmitri Mendeleev ( )
In 1869, Mendeleev developed the periodic classification of elements
Arranged 63 known elements in order of atomic mass
Placed elements with similar
physical and chemical properties
in the same group
Left gaps in the table for
elements yet to be discovered

5. Overview (so far)

6. Metals Found on the left side of the staircase (under the stairs)
Physical properties
Solid at room temperature (except mercury)
Lustre (shine)
Conducts heat/electricity
Malleable (bendable)
ductile (stretched into wires) as solid
High melting and boiling points

7. Non-Metals
Found on the right side of the staircase (to the right of the staircase)
Physical Properties
Solid, liquid or gas at room temperature
NOT lustreous
Brittle, hard, or soft
POOR conductors
The opposite to the metals!

8. Metalloids Found touching the stairs
Have BOTH metallic and non metallic properties
Physical properties tend to be that of metals
Chemical properties tend to be that of non-metals
Used in computer industry

9. Metalloids Groups 3-12 Generally stable metals
Not as easily predictable
Many form ions with more than one possible charge
Most common indicated on periodic table by the top number

10. Trends Elements arranged according to their properties and atomic mass
All elements in the same period have the same ENERGY LEVELS
Elements of the same group have the same number of VALENCE ELECTRONS

11. Groups to know!
Group 1 –
Group 2 –
Group 17 –
Group 18 –

13. Alkali Metals Very reactive Donate one electron
Very soft, do not occur freely in nature
Why do you think that is?

14. Alkaline Earth Metals
Berylium
Magnesium
Calcium
Strontium
Barium

15. Halogens
Fluorine
Chlorine
Bromine
Iodine
Astatine

16. Noble Gases
Helium
Neon
Argon
Krypton
Xenon
Radon