1. The Periodic Table

2. In 1860, grouped elements based on solitaire.
Dmitri Mendeleev-
In 1860, grouped elements based on solitaire.
He arranged elements in increasing mass.
Left spaces for new elements to be discovered.

3. Mendeleev’s Periodic Table
DM’s periodic table had blank spaces where no known element would fit.
Predicted the existence of undiscovered elements that would one day be found and fall into the blocks.
He was correct!

4. Design of the Table Columns = families or groups.
Elements in same family have similar prop.
18 total families, but only 8 main ones.
Main Groups 1 2 3 4 5 6 7 8

5. Alkali Metal Family (Group 1)
1st family of periodic table
All have 1 valence e- which they lose.
Atom gets overall charge of +1. (Why?)
Very reactive.

6. Alkaline Earth Metal Family (Group 2)
2nd family
Have 2 valence e- which they lose.
Get charge of +2.
Very reactive.

7. Boron, Carbon, and Nitrogen Families
Boron Family
Have 3 valence e-.
Form +3 charge.
Carbon Family
Have 4 valence e-.
Get charge of +4 or +2.
Nitrogen Family
Have 5 valence e-.
Get charge of -3

8. Oxygen Family, Halogens, and Noble Gases
Have 6 valence e-.
Form -2 charge.
Halogens
Have 7 valence e-.
Form -1 charge.
Noble Gases
Have 8 valence e-.
Stable / Unreactive
Because their energy levels are full
Do not gain or lose e-.

9. Transition Metals Transition metals Central area of periodic table.
Most have 1 or 2 valence e-.
Properties similar to each other and to other metals.

10. Rare Earth Elements At bottom of table. 1st Row = Lanthanide Series
Put there to make the table shorter / easier to read.
Similar to each other.
1st Row = Lanthanide Series
2nd Row = Actinide Series
All actinides are radioactive.

11. Design of the Table Rows = periods.
Elements in a period do not have similar props.
Their properties repeat from period to period.
There are 7 main periods. 1 2 3 4 5 6 7

12. Design of the Table
Don’t mistake the two rows at the bottom of the table for periods!!
They are separated out to make the table shorter and easier to read.
They actually belong to the 6th and 7th periods.

13. Element Key 6 C carbon 12.011 atomic number chemical symbol
Every table should have a key to tell you what each thing in an element’s box stands for. 6
atomic number C
chemical symbol
carbon
element name
12.011
atomic mass

14. Properties of Elements
Metals Metalloids Nonmetals

15. Metals – MOST of the Periodic Table
Good conductors of heat and electric current
High luster or sheen (shiny)
Solids at room temperature (except for Hg)
Ductile
Malleable
MORE REACTIVE ON LEFT

16. Nonmetals – upper right corner
Variation in properties
Not metals
Mostly gases at room temperature
Generally, poor conductors
Solids tend to be brittle

17. Metalloids – the “stairstep”
Properties similar to metals and nonmetals
Behavior (metal or nonmetal) depends on conditions

18. Valence Electrons Valence e- Valence #
Number of e- in the outer energy level of an atom.
Determine the properties of an element.
Valence #
Bonding ability of the atom
How many e- the atom will gain or lose when comb. w/ another atom
Related to the charge of the ion
Don’t get these two mixed up!

19. Valence Electrons vs Valence Number
An oxygen atom has 6 valence electrons.
But its valence number is 2. That’s because oxygen normally only forms 2 bonds with other atoms.

20. Check for Understanding
Is the element at right a metal, metalloid, or non-metal?
Answer: Metal
How many valence electrons does this element have?
Answer: 1
How many electrons will this element gain or lose?
Answer: It will lose 1 electron.
What is this element’s valence number?
What charge will this element have when it gains or loses electrons?
Answer: +1 11 Na
Sodium
22.99

21. Check for Understanding
Is the element at right a metal, metalloid, or non-metal?
Answer: Non-metal
How many valence electrons does this element have?
Answer: 7
How many electrons will this element gain or lose?
Answer: It will gain 1 electron.
What is this element’s valence number?
Answer: 1
What charge will this element have when it gains or loses electrons?
Answer: -1 17 Cl
Chlorine
35.45

22. Check for Understanding
Is the element at right a metal, metalloid, or non-metal?
Answer: Metal
How many valence electrons does this element have?
Answer: 3
How many electrons will this element gain or lose?
Answer: It will lose 3 electrons.
What is this element’s valence number?
What charge will this element have when it gains or loses electrons?
Answer: +3 13 Al
Aluminum
26.98

23. Check for Understanding
Is the element at right a metal, metalloid, or non-metal?
Answer: Non-metal
How many valence electrons does this element have?
Answer: 8
How many electrons will this element gain or lose?
Answer: It does not gain or lose electrons.
What is this element’s valence number?
Answer: 0
What charge will this element have when it gains or loses electrons?
Answer: None 36 Kr
Krypton
83.80

24. Check for Understanding
Is the element at right a metal, metalloid, or non-metal?
Answer: Metalloid
How many valence electrons does this element have?
Answer: 3
How many electrons will this element gain or lose?
Answer: It will lose 3 electrons.
What is this element’s valence number?
What charge will this element have when it gains or loses electrons?
Answer: +3 5 B
Boron
10.81