1. THE PERIODIC TABLE

2. SCIENTISTS INVOLVED IN THE PERIODIC TABLE DEVELOPMENT
Newlands—English scientist who first arranged elements according to increasing atomic mass (developed no table or chart)
Found similar element properties every 7 spaces apart; later became 8 spaces apart after adding noble gases (AKA Law of Octaves)

3. Mendeleev—Russian chemist who arranged the known 63 elements based on increasing atomic mass so that elements with similar properties fell into the same column on his table; gaps in his table were elements that he predicted the properties of (Sc, Ga, Ge)
Periodic—repeating according to a pattern (Ex: days of the week)

4. Ramsay—added the last column to Mendeleev’s table
Moseley—British scientists who determined the atomic #s of elements using X-rays; he is who our modern table is based on

5. Periodic law
States that an element’s chemical and physical properties are periodic functions of their atomic #s
As you go across a period (series)—start with reactive metal solid and end with nonreactive (inert) nonmetal gas
Going down a group (family)---elements have similar chemical and physical properties

7. Metals Nonmetals Metalloids magnetic not Means “metal-like”
Malleable AND
Ductile
brittle
Have at least 1 side of its element box touching staircase
(8 total because Al is a metal)
Have luster
dull
White/gray in color
Good conductor
Good insulator
AKA semi-conductors
High corrosion
Low corrosion
High density
Low density
High melting pt./boiling pt.
Low melting pt./boiling pt.

8. Form Positively charged cations Form Negatively charged anions
Metals
Nonmetals
Lose electrons
Gain electrons
Form Positively charged cations
Form Negatively charged anions
Found left of the staircase line
Found right of the staircase line
React with acids to form hydrogen gas
Do not

9. Element Families (Groups)
Family/Group Name
Characteristics
Alkali metals (1A)
Most reactive metal family (Francium is most reactive); have 1 valence electron; +1 oxidation number
Alkaline earth metals (2A)
Have 2 valence electrons;
+2 oxidation number
Transition Metals
AKA “B” groups; have varying oxidation numbers
Boron family (3A)
Contains 1 metalloid and 4 metals;
3 valence electrons
+3 oxidation number
Carbon family (4A)
Contains 1 nonmetal, 2 metalloids, & 2 metals;
4 valence electrons
+ and -4 oxidation number
Nitrogen family (5A)
5 valence electrons;
-3 oxidation number
Oxygen family (6A)
6 valence electrons; -2 oxidation number
Element Families (Groups)

10. Continued Halogens (7A)
Most reactive nonmetal family (Fluorine is most reactive and has highest electronegativity);
7 valence electrons
-1 oxidation number;
Name means “Salt formers” in Greek
Noble Gases
AKA inert gases;
Do not react to form compounds due to full valence electron shell
All have 8 valence electrons (Except He)
Lanthanide Series
AKA Rare earth metals;
belong in row 6 due to their atomic number (sometimes known as inner transition metals)
Actinide Series
Belong in row 7 due to their atomic number (sometimes known as inner transition metals);
Are radioactive
Continued

11. Representative Elements (Main Group Elements)
All “A” groups because their “A” column number represents how many valence electrons they have
Oxidation number---refers to how many valence electrons are lost or gained in order to bond
Oxidation number pattern For “A” groups:
+1, +2, +3, + and -4, -3, -2, -1, 0

12. Atoms vs. Ions Atoms Ions Are electrically neutral
Can have positive or negative charge
Protons = electrons
Have lost or gained electrons
Can be cations which are
1. positive
2. have lost electrons
3. are characteristic of metals
4. are smaller than the original atom
Can be anions which are
Negative
Have gained electrons
Are characteristic of nonmetals
Are larger than the original atom

13. Practice Questions 1. Which is smaller: S-1 OR S-2
2. Which is smaller: Sn+2 OR Sn+4
3. Which is larger: Al OR Al+3
4. Which is larger: N-3 OR N