1. Chapter 11 Introduction of Atoms
Name: ________________
Class: ___________

2. In the Beginning… 440 BCE… first atomic theory by Democritus
History of the atom:
In the Beginning…
440 BCE… first atomic theory by Democritus
Atom: Greek meaning “not able to be divide”
Small hard particles that make up stuff (matter)
Countered by Aristotle, stated never end up with something that cannot be divided

3. Dalton’s Theory John Dalton came up with the new theory
1700’s scientists learn elements combine in certain proportions based on mass
1803 theory
All substances made up of atoms
Atoms of the same elements are exactly alike
Atoms join with other atoms to make new substances
(Not quite correct)

4. We’re getting closer….
J.J. Thomspon discovered atoms are composed of smaller particles
Discovered negative particles which he named ELECTRONS
Plum-Pudding Model: electrons are located all around an atom

5. Rutherfords Thoery
1909: experimented with “plum pudding” and discovered atoms more of a solid substance
1911: Revised theory to state center of atom has a nucleus (dense positively charged area) and electrons surround and are repelled by nucleus

6. Bohr’s Idea
1913: electrons move around the nucleus in certain paths, energy levels
Electron can “jump” paths

7. Schrodinger and Heisenberg Idea
Explained the nature of electrons in added
Do not travel in definite paths; paths cannot be predicted
Theory states; there are regions in an atom where electrons are likely to be found called clouds

8. Atoms
the smallest part of an element that has all the element’s properties.
Composed of PROTONS and NEUTRONS and (found in the nucleus) ELECTRONS that revolve swiftly around the nucleus.

9. Structure PROTONS are positively charged particles
NEUTRONS have no charge, but have mass
ELECTRONS are smallest and electrically negative
The number of Protons and Electron ARE EQUAL
ATOMIC NUMBER is equal to the number of electrons which is also the proton number
ALWAYS A WHOLE NUMBER
ATOMIC MASS is the number of neutrons and protons.
HAS DECIMALS DUE TO NEUTRONS

10. Electrons and Energy Levels
Electrons swarm around the nucleus of an atom in layers “clouds”
Each cloud has a minimum and maximum number of electrons it can hold
The maximum number of layers is 7
The maximum number of electrons in each level is respectfully inner to outer: 2, 8, 8, 18, 18, 32, and 32

11. Chapter 12 The Periodic Table
Name: ________________
Class: ___________

12. Arrangement of Elements
Scientists were needing a way to arrange the elements.
1869: Dmitri Mendeleev arranged elements by increasing atomic mass and discovered a pattern called “PERIODS”
Wasn’t a perfect fit, and needed retuning

13. Periodic Table
1914: Henry Moseley arranged the elements by atomic number
Solved the problem of missing elements/spaces in the table
Periodic Law: the physical and chemical properties of an element changes with its atomic number

14. Classifying Atoms Organize the atoms by their elements
Classified by similar CHEMICAL CHARACTERISTICS(columns/groups) and INCREASING ATOMIC NUMBER (rows/periods)
Location will help you predict how it will react with others in bonding.

15. Metals Nonmetals Metalloids Found on the left of the periodic table
Few electrons in outer shell
Solids
Nonmetals
Right if the “zigzag” line on periodic table
Almost complete electron shells
Mostly gases at room temperature
Metalloids
“semiconductors”
Border left side of “zigzag”
Varying number of electrons in outer shell
Share properties of both metals and nonmetals

18. Decoding the Table
Each element has a symbol made from its name; either English or Latin root
Rows are the periods that show a pattern of change in physical and chemical properties are you move across left to right
Vertical columns are groups/families
Similar chemical/physical prosperities

19. We are Familiy…. Each group of elements share similar properties
Most family names are the name of the element at the top of the column
Some family names are notable based on certain traits

20. Alkali Metals
Group 1
Most reactive metals, the bottom element, Francium, is the most reactive element known.
Stored in oil to keep from reacting with air (moisture)
1 electron in their outermost shell

21. Alkaline-Earth Metals
Group 2
2 electrons in the outermost shell
Less reactive than group 1

22. Group 3 Transition Metals, columns 3 to 12
Less reactive than group 1 or 2
Usually have 1 to 2 electrons in outermost shell, (except mercury)
Good conductors of thermal energy and electricity

23. Lanthanides and Actinides
Appear in separate “rows” outside the body of the table
Elements have very similar properties
Lanthanides: shiny, reactive metals
Actinides: radioactive or unstable
ELEMENTS HIGHER THAN 94 ARE NOT FOUND NATURALLY; PRODUCED IN LABORATORIES

24. Boron Group Group #13 Contains 1 metalloid and 4 metal elements
3 electrons in outer level
Solids at room temperature
Most common element is Aluminum

25. Carbon Group Group 14 1 nonmetal, two metalloids, 2 metals
4 electrons in the outermost shell
Reactivity varies among elements
Solid at room temperature

26. Nitrogen Group Group 15 2 nonmetals, 2 metalloids, and 1 metal
5 electrons in outermost shell
Reactivity varies with elements
Solid at room temperature (except nitrogen)

27. Oxygen Group Group 16 Three nonmetals, one metalloid, 1 metal
6 electrons in the outermost level
Reactive to other elements
All but oxygen are solids at room temperature

28. Halogens Group 17 Nonmetal elements 7 electrons in outermost shell
Very reactive; VIOLENT reactions with alkali metals to form salts; never found by self in nature
Poor conductors of electric current

29. Nobel Gases Group 18 Nonmetal elements
8 electrons in outermost shell; except Helium which is 2
UNREACTIVE
Colorless, odorless gases at room temperature

30. Hydrogen Properties are unique to itself
most abundant element in universe
1 electron in outermost shell
Colorless, odorless gas at room temperature
Low density
EXPLOSIVE REACTIONS WITH OXYGEN