1. Periodic Table and Chemical Properties
Science 9

2. Objectives Describe the history of the periodic table
Know the type of information that can be found on the periodic table
Understand the difference between Metals, Non-metals and Metalloids

3. Origin of Periodic Table
19th century chemists wanted to organize their observations of the elements
Wanted to group elements with similar properties together
1867 Dmitri Mendeleev made a card for every known element
He included density, colour, melting
& boiling point
He used these cards to sort and
re-sort until he found a pattern

4. Origin of Periodic Table
Many scientists were trying to organize the elements
Mendeleev was successful since he realized there needed to be holes left for undiscovered elements
Mendeleev was able to predict the properties of elements that were later discovered from the placement of the holes and the surrounding known elements

5. Information on Periodic Table
Periodic Table contains a lot of information
Name
Symbol
Atomic number
Atomic mass
Ion charge

6. Periodic Table – Symbol and Name
Symbol is generally the largest piece of information
Name is usually written underneath of the symbol

7. Periodic Table – Atomic Number
Atomic number = the number of protons
It is always a whole number (not a decimal or fraction)
Pattern?
starts at number 1 and increases in a regular way down the table

8. Periodic Table – Atomic Mass
Mass of average atom of an element
Measured in atomic mass units (amu)
Pattern?
Tends to increase along with atomic number
*exceptions do occur
ex. Cobalt and Nickel

9. Periodic Table – Ion Charge
Ion charge – electrical charge that forms on an atom when it gains or loses electrons
Some elements have multiple ion charges
Pattern?
Elements on right side of table generally positive. Elements on the right hand side are generally negative

11. Metals, Non-metals and Metalloids
Elements can be categorized into three groups
1. Metals
2. Non-metals
3. Metalloids

12. Metals, Non-metals and Metalloids
Metals: typically hard, shiny, malleable, ductile, and good conductors of heat and electricity
Non-metals: Do not have the above properties, generally gases or brittle solids at room temperature
Metalloids: elements that share some properties with metals and some properties with non-metals

13. Metals, Non-metals and Metalloids

14. Metals, Non-metals and Metalloids
The Periodic table is organized so elements with similar properties are grouped together. Where are the metals located?
Where are the non-metals located

15. Ele

16. Metals, Non-metals and Metalloids
Staircase line starting next to Boron
Metals are on the left side of this line
Non-metals (except for Hydrogen) are located on the right side of this line
Metalloids are elements whose box shares a border with the staircase line is a metalloid.