1. Elements, Atoms, and Ions

2. The Language of Chemistry
The elements, their names, and symbols are given on the PERIODIC TABLE
How many elements are there?

3. The Periodic Table Dmitri Mendeleev (1834 - 1907)
Hi, my name’s Dimitri. I like long walks on the beach, meteorology, studying fossil fuels and hot air balloons.
Dmitri Mendeleev ( )

4. Glenn Seaborg (1912-1999 ) Discovered 8 new elements.
Only living person for whom an element was named.

5. The Periodic Table

6. Periods in the Periodic Table

7. Groups in the Periodic Table
Elements in groups react in similar ways!

8. Regions of the Periodic Table

9. Group 1A: Alkali Metals Reaction of potassium + H2O
Cutting sodium metal

10. Group 2A: Alkaline Earth Metals
Magnesium
Magnesium oxide

11. Group 7A: The Halogens (salt makers) F, Cl, Br, I, At

12. Group 8A: The Noble (Inert) Gases He, Ne, Ar, Kr, Xe, Rn
Lighter than air balloons
“Neon” signs
Very Unreactive because they have full electron levels
XeOF4

13. Transition Elements Iron in air gives iron(III) oxide
Lanthanides and actinides
Iron in air gives iron(III) oxide

14. The Atom nucleus (of protons and neutrons)
An atom consists of a
nucleus
(of protons and neutrons)
electrons in space about the nucleus.
Electron cloud
Nucleus

15. The Language of Chemistry
CHEMICAL ELEMENTS -
pure substances that cannot be decomposed by ordinary means to other substances.
Aluminum
Bromine
Sodium

16. CHEMICAL COMPOUNDS are composed of atoms and so can be decomposed to those atoms.
The red compound is composed of • nickel (Ni) (silver) • carbon (C) (black) • hydrogen (H) (white) • oxygen (O) (red) • nitrogen (N) (blue)

17. Compounds composed of 2 or more elements in a fixed ratio
properties differ from those of individual elements
EX: table salt (NaCl)

18. A MOLECULE is the smallest unit of a compound that retains the chemical characteristics of the compound.
Composition of molecules is given by a MOLECULAR FORMULA
H2O
C8H10N4O2 - caffeine

19. ELEMENTS THAT EXIST AS DIATOMIC MOLECULES
Remember:
HOFBrINCl
These elements only exist as PAIRS. Note that when they combine to make compounds, they are no longer elements so they are no longer in pairs!