1. A Brief History of the Elements

2. Any pure substance that is made of only one kind of atom
Element
Any pure substance that is made of only one kind of atom

3. History of Elements Aristotle
Aristotle believed there were four “elements”: air, fire, water, and earth.
People during Aristotle’s time period knew of at least nine substances that are defined as elements today.

5. History of Elements Alchemists
Alchemists tried to convert “cheap” metals, like lead, into gold.
In doing so, they developed equipment and techniques that enabled them to discover and purify substances.

6. History of Elements Alchemists
Alchemy also had a philosophical, magical, and mystically religious aspect to it.

7. History of Elements
Alchemy was transformed into a real science after the Renaissance.
Boyle rejected Aristotle’s elements and defined an element as any substance that cannot be decomposed into simpler substances.

8. Element Symbols
Berzelius proposed element symbols consisting of the first two letters of the element’s Latin name.

9. Element Symbols
In the current periodic table, each symbol still consists of a letter or two from the element’s name.
Most of the symbols are derived from the English names instead of the Latin.

10. Element Symbols
You will need to memorize the symbols for several common elements.
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11. Familiar Elements and Their Symbols
aluminum Al
copper Cu
mercury Hg
radium Ra
argon Ar
fluorine F
neon Ne
radon Rn
arsenic As
gold Au
nickel Ni
silicon Si
barium Ba
helium He
nitrogen N
silver Ag
bromine Br
hydrogen H
oxygen O
sodium Na
calcium Ca
iodine I
phosphorus P
sulfur S
carbon C
iron Fe
platinum Pt
tin Sn
chlorine Cl
lead Pb
plutonium Pu
tungsten W
chromium Cr
magnesium Mg
potassium K
uranium U

12. Element Symbols
Some symbols still use letters from the element’s Latin name.
Silver, Ag - argentum
Sodium, Na - natrium
Iron, Fe - ferrum
Lead, Pb - plumbum

13. Element Symbols
Some elements are named for scientists, places, or colors.

14. Characteristics of Elements
Almost all naturally-occurring elements are solids at room temperatures.
Two are liquids, and eleven are gases.

15. Characteristics of Elements
Some elements naturally occur as separate atoms.
These elements are called monatomic.
They are located at the far right of the periodic table.

16. Characteristics of Elements
Some elements exist as molecules consisting of two atoms.
These elements are called diatomic.

17. Characteristics of Elements
Hydrogen, nitrogen, oxygen, and the halogens are diatomic molecules.
The halogens are the four elements on the right side of the periodic table (shaded light purple).

18. The Diatomic Molecules
Characteristics of Elements
The Diatomic Molecules
H N O H a l o g e n s

20. Characteristics of Elements
Anytime an element occurs in a molecule with more than two atoms, it is called a polyatomic molecule.
Oxygen can form O3 (ozone) or O4 (tetraoxygen).
Sulfur can occur as S7, S8, or S12.

21. Who proposed symbols consisting of the first two letters of an element’s Latin name?
Aristotle
Berzelius
Boyle
The Alchemists

22. Which of the following is not a diatomic molecule?
Chlorine
Iodine
Oxygen
Sulfur