1. The Periodic Table

2. Pre-Periodic Table Chemistry …
…was a mess!!!
No organization of elements.
Difficult to find information.
Chemistry didn’t make sense.

3. Dmitri Mendeleev Father of the Periodic Table
WHAT HE DID…
Put elements in rows by increasing atomic weight
Put elements in columns by the way they reacted.
SOME PROBLEMS…
He left blank spaces for what he said were undiscovered elements.
He broke some patterns

4. The Current Periodic Table
Now the elements are put in rows by increasing atomic number
The horizontal rows are called periods and are labeled from 1 to 7.
The vertical columns are called groups or families are labeled from 1 to 18.

5. 6.1
The Periodic Law
States that when elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
This allows us to put elements in order and make predictions about their behavior

6. Alkali Metals
1st column on the periodic table, not including hydrogen. (Group One)
Are very reactive
their reactivity increases moving down the group

7. Alkaline Earth Metals Second column on the periodic table (Group 2)
Reactive metals
Several of these elements are important mineral nutrients (such as Mg and Ca)
All are solids

8. Transition Metals Elements in groups 3 – 12 Less reactive metals
Not as predictable as other metals
Have a wide variety of properties
Hg is the only liquid; all others are solid

9. Halogens Elements in group 17 Very reactive nonmetals
Fluorine is the most reactive
this decreases as you move down the group
F and Cl are gas; Br is liquid; I and At are solid

10. The Noble Gases Elements in group 18
Extremely low chemical reactivity or inert (very stable)
Used in common items such as neon signs or balloons
All are gas

11. Lanthanides & Actinides
Lanthanides: atomic numbers 57 – 71 (top row)
Actinides: atomic numbers 89 – 103 (bottom row)
All solid

12. Metals, Nonmetals, and Metalloids
6.1
Metals, Nonmetals, and Metalloids
One way to classify elements in the periodic table is as metals, nonmetals, and metalloids. Inferring What is the purpose for the black stair-step line?

13. Metals To the left of the staircase line
Physical Properties:
Luster (shiny)
Good conductors
High melting point
Malleable
Chemical Properties:
Easily lose electrons
Corrode easily
(rusting or tarnishing)

14. Non-metals to the right of the staircase line
Chemical Properties:
Tend to gain electrons
Physical Properties:
Dull (not shiny)
Poor conductor of electricity
Brittle
Low Melting Point

15. Metalloids along the staircase line
Solids
Shiny or dull
Malleable
Conduct heat and electricity better than non metal but not as well as metals

16. Protons, Neutrons, Electrons
Protons are positively charged particles in the nucleus
Neutrons are neutral particles also in the nucleus
Electrons are negatively charged particles that surround the nucleus
Atomic Mass Number = # protons + # neutrons
# Protons = Atomic #
# protons = # electrons

17. Example Element Atomic # Atomic Mass Atomic Mass # Protons Neutrons
Electrons P 15
30.974 20 36

18. Ions
Ions are charged particles that have either lost or gained electrons
Non-metals gain electrons (- charge)
Metals lose electrons (+ charge)
Ex: Calcium ion: Ca2+ (loses 2 electrons)
Oxide ion: O2- (gains 2 electrons)

19. Example Element Atomic # Atomic Mass # Protons Neutrons Electrons
Charge
P3- 15 -3 20 +2
Br- 36