1. The Periodic Table (6.1)

4. Elements At the present time 114 elements are known.
These elements vary widely in their abundance
For example, only five elements account for over 90% of the Earth's crust: oxygen, silicon, aluminum, iron, and calcium.
In contrast, just three elements (oxygen, carbon, and hydrogen) account for over 90% of the mass of the human body.

6. Elements The Periodic Table pure substances that cannot be broken down
into a simpler chemical substance by any
physical or chemical means

7. Symbols for Elements Symbols consist of one or two letters.
The first letter is always UPPERCASE.
If there is a second letter, it is always lowercase.
H He Ca
Hydrogen Helium Calcium

8. Compounds
a pure substance composed of two or more
different elements that are chemically joined

9. H2O Symbols for Compounds Symbol for the element hydrogen
Symbol for the element oxygen
H2O
The small number (subscript) after the element tells us the number of atoms of that element. (There are 2 atoms of hydrogen in this compound)
If there is no small number (no subscript) after the element, there is only 1 atom of that element. (There is 1 atom of oxygen in this compound)

10. Families
used to describe columns in the table
Column
  

11. Metals, Non-metals, Metalloids
**draw a staircase onto your own copy of the periodic table

12. everything to the left of the staircase is a metal
everything to the right of the staircase is a non-metal
Elements located along the staircase line (except Al) are called metalloids because they have properties of both metals and non-metals.

13. Properties of Non-Metals
Properties of Metals
shiny
good conductors of heat and electricity
Usually solid (except mercury – liquid)
Malleable
ductile
Properties of Non-Metals
dull
poor conductors of heat and
electricity
Solids, liquids, or gases
brittle

14. State of Element at Room Temperature
Solids: most of the elements on the table occur in this state at room temperature
Liquids: only mercury (Hg) and bromine (Br) can be found as liquids at room temperature
Gases: many of the non-metals and hydrogen (H)

15. Reactivity
The alkali metals are the most reactive metals (Francium is the most reactive)
The most reactive non-metals are the halogens (Fluorine is the most reactive)
The noble gases are stable and do not react with anything

16. Alkali Metals

17. Periodic Table Video Homework: p. 215 #1-10
Homework: p. 215 #1-10