1. Organizing the Elements
Section 1:
Organizing the Elements

2. Periodic – repeating according to some pattern
In his periodic table, Mendeleev arranged elements in rows by increasing atomic mass.
Mendeleev was able to predict new elements and left spaces in his table to make the pattern fit and successfully predict the existence and properties of elements not yet discovered.

3. The modern periodic table organizes elements by atomic number.
When the elements are arranged in this way, elements that have similar properties appear at regular intervals (periodic)
periodic law: the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements

4. Changing the Arrangement
period: a horizontal row of elements in the periodic table
Elements become less metallic across each period.
group: a vertical column of elements in the periodic table; elements in a group share chemical properties
Elements in a group have similar properties.

5. Exploring the Periodic Table
Section 2:
Exploring the Periodic Table

6. The Role of Electrons
The periodic trends in the periodic table are the result of electron arrangement.
Valence electrons account for similar properties.
If an atom gains or loses electrons, it no longer has an equal number of electrons and protons. Because the charges do not cancel completely, the atom has a net electric charge.

7. created when electrons are removed.
Ion Formation
Cations positive ions
created when electrons are removed.
Anions - negative ions
created when electrons are gained

8. Elements are classified in one of the following ways:
metal: an element that is shiny and that conducts heat and electricity well
nonmetal: an element that conducts heat and electricity poorly
semiconductor (or metalloid): an element or compound that conducts electric current better than an insulator does but not as well as a conductor does

9. Properties of Metals

10. Properties of Nonmetals

11. Properties of Semiconductors (AKA  Metalloids)

12. Section 3:
Families of Elements

13. In general, the elements in a family have the same number of valence electrons.

14. Families of metals
alkali metal: one of the elements of Group 1 of the periodic table, has only 1 valence electron
alkaline-earth metal: one of the elements of Group 2 of periodic table, has 2 valence electrons
transition metal: one of the metals that can use the inner shell before using the outer shell to bond

15. Families of nonmetals
The noble gases are relatively inert or unreactive, because their s and p orbitals are filled.
In general, they do not form ions or compounds.
The halogens combine easily with metals to form salts.
Halogen means “salt former”
Have 7 valence electrons

16. Semiconductors
As their name suggests, they are able to conduct heat and electricity under certain conditions.
AKA  Metalloids
They are located in the stairstep