1. The Periodic Table
Chapter 27

2. Dmitri Mendeleev
The Russian chemist Mendeleev came up with the idea of the periodic table of elements.
His idea brought order to the properties of elements.

3. The Periodic table.
The periodic table is an arrangement of elements in order of increasing atomic number.
The Atomic number is the number of protons in the nucleus of an atom.

4. Groups
Elements that behave in a similar way are arranged in vertical columns called groups.
A group is a vertical column of elements that all have the same number of electrons in the outer shell.
All elements in a group behave in a similar manner chemically.

5. Group 1- Alkali Metals
Examples- Alkali metals Lithium, Sodium, Potassium.(Li, Na, K.)
Each element has 1 electron in its outer shell.
The elements have similar chemical properties.

6. Group 2 Alkali Earth metals
Group 2 – Alkali Earth metals. Be Mg Ca.
Each element has 2 electrons in its outer shell.

7. Group 7 – Halogens Group 7 – Halogens
Fluorine, Chlorine, Bromine.(Fl, Cl, Br)
Each element has 7 electrons in its outer shell.

8. Group 8-Nobel Gases
All the elements in group 8(except Helium) have 8 electrons in their outer shell.
This makes them stable and un-reactive.

9. The Periodic Table

10. Periods The horizontal rows of elements are called Periods
The period tells the number of shells in the atom of an element
The 1st period has 2 elements H and He.
The 2nd period goes from Li to Ne.
The 3rd period goes from Na to Ar.

11. Metals and Non-metals The elements of the periodic table can be
divided into metals
and non-metals.
Common Metals
include:
Copper(Cu)
Zinc(Zn)
Iron(Fe)
Silver(Ag)
Gold(Au)