1. 15.1 The Periodic Table of the Elements

2. Periodic Table Timeline
Lavoiser ( ) Composed the first list of 33 elements. Distinguished metals from nonmetals.

3. Meyer (1869) Compiled a periodic table with elements arranged by atomic weight. Elements with similar properties arranged in columns.
Mendeleev (1869) Created a periodic table with elements arranged by atomic weight. Elements with similar properties arranged in columns.
Moseley (1914) Determined atomic numbers of each element.

4. 15.1 Physical properties
Remember phase changes are physical changes.

5. 15.1 Chemical properties
Any change that transforms one substance into a different substance is called a chemical change.

6. 15.1 The Periodic Table
The periodic table organizes the elements according to how they combine with other elements (chemical properties).
The periodic table is organized in order of increasing atomic number.

7. 15.1 The Periodic Table Each horizontal row is called a period.
Each vertical column is called a group or family.

9. Elements
Metals
Nonmetals
Metalloids

10. Metals Almost 75% of elements are metals
Most are solids at room temperature
exception-Hg(mercury)

11. Alkali Metals(Group 1) Very reactive Shiny and light weight
Only found combined with other elements
One electron in their outer shell

12. Alkaline Earth Metals (Group 2)
Not as reactive as the alkali metals
Have 2 electrons in the outer shell

13. Transition Metals (Groups 3 to 12)
Less reactive than alkali or alkaline earth metals
Properties vary widely examples: Hg –liquid, titanium is not very reactive but iron is.
Electrons in the 2 outer most shells can bond with other elements

14. Lanthanides/Inner Transition Metals
Follow the element lanthanum
Shiny and reactive
Used to make different types of steel

15. Actinides
Follow the metal actinium
Radioactive
Unstable

16. Groups with Metalloids
Groups 13 to 16 shift from metals to nonmetals with some metalloids in between
They have properties of both metals and nonmetals

17. Groups 13 to 16 Boron Group - 3 electrons in the outer shell
Carbon Group -4 electrons in the outer shell
Nitrogen Group - 5 electrons in the outer shell
Oxygen Group- 6 electrons in the outer shell

18. Halogens(Group 17) Very reactive nonmetal
Seven electrons in the outer shell
Often bond with metals
Fluorine is the most reactive
Never found uncombined in nature
Form halides-a halogen combined with another element to form a compound

19. Noble Gases (Group 18) Have full outer shell with 8 electrons
Rarely combine with other elements
Non-reactive (inert)
Colorless and Odorless
Gases at room temperature

20. HYDROGEN Stands apart Only 1 electron in the outer energy level
Very reactive
Other properties: colorless, odorless gas at room temperature; low density; reacts explosively with oxygen.

21. Energy Levels And The Periodic Table
The periods (rows) of the Periodic Table correspond to the energy levels in the Bohr model of the atom. The first energy level can accept up to two electrons therefore Period 1 is the first energy level.
Period 2 is the 2nd energy level
Period 3 is the third energy level and so on.

22. Energy Levels And The Periodic Table
The outermost electrons in an atom are the ones that interact with other atoms. They are also the electrons that are in the highest energy level.
Electrons in the completely filled inner energy levels do not participate in forming chemical bonds.