1. Electrons and the Periodic Table
Mrs. Freeman

2. History HOW WAS MENDELEEV’S PERIODIC TABLE ARRANGED?
By their chemical properties
 HOW IS THE MODERN PERIODIC TABLE ARRANGED?
By increasing number of protons and atomic mass.
WHY DIDN’T MENDELEEV ARRANGE HIS TABLE THIS WAY?
Because at the time the number of protons was not known.

3. PERIODS: are a horizontal row of elements.
HOW MANY: 7
VARIATION ACROSS A PERIOD: Changes from metals to metalloids to nonmetals

4. GROUPS AKA FAMILIES: the individual columns of elements.
HOW MANY? 18
SIMILARITIES BETWEEN ELEMENTS IN THE SAME GROUP?
They have the same number of valence electrons

5. THREE CLASSES OR CATEGORIES OF ELEMENTS ON THE PERIODIC TABLE
METALS
NONMETALS
METALLOIDS
LOCATION
Left side of the stair step line
Right side of the stair step line
Along the stair step line
EXAMPLES AND USES
Zinc-vitamins and certain containers.
Potassium-in bananas for cells to use
Oxygen-gas to breathe
Carbon-foundation for life.
Aluminum- cans, canisters, cars.
Silicon-sealant against water
PROPERTIES
Hard, malleable, durable, rust, dense
Not dense, colorless,
Has properties of both metals and non-metals.

6. REACTIVITY PATTERN WITHIN A GROUP: increasing reactivity, decreasing melting and boiling point and density generally increases,
Metals
Left side of the table
Nonmetals
Right side of the table

7. 1 2 13 14 15 16 17 18 3 4 5 6 7 8 ALKALI METALS ALKALINE EARTH METALS
BORON FAMILY
CARBON FAMILY
NITROGEN FAMILY
OXYGEN FAMILY
HALOGENS
NOBLE GASES
GROUP # 1 2 13 14 15 16 17 18
LIST OF ELEMENTS IN GROUP
Hydrogen
Lithium
Sodium
Potassium
Rubidium
Cesium
Francium
Beryllium
Magnesium
Calcium
Strontium
Barium
Radium
Boron
Aluminum
Gallium
Indium
Thallium
Carbon
Silicon
Germanium
Tin
Lead
Nitrogen
Phosphorus
Arsenic
Antimony
Bismuth
Oxygen
Sulfur
Selenium
Tellurium
Polonium
Fluorine
Chlorine
Bromine
Iodine
Astatine
Helium
Neon
Argon
Krypton
Xenon
Radon
# of valence electrons 3 4 5 6 7 8
Key Facts
Prop. And
Reactivity
Uses
Are very reactive.
Form Ionic Compounds
Metal
Ex. Salt
React with halogens well.
Form ionic compounds.
Ex. Magnesium chloride
Forms covalent compounds
Non-metals
Boron is metalloid.
Forms both covalent and ionic bonds.
2 metals and 2 metalloids
Forms covalent bonds.
Basis for fertilizer
Forms covalent and ionic bonds.
Most abundant elements in earths crust.
All are non-metals.
Most reactive group.
Inert-do not react

8. THE MOST REACTIVE METALS:
Francium, Cesium, and Rubidium (in order from most reactive to least reactive)
THE MOST REACTIVE NONMETALS:
Fluorine, Chlorine, and Bromine (in order from most reactive to least reactive)

9. Excited electron-
an electron in an energy level higher than its ground state (it has absorbed energy)

10. Ground state-
all the electrons have the lowest possible energy.

11. Energy Level-
The possible energies that electrons in an atom can have.

12. Sub-level Electron orbital designated s, p, d or f.
These sublevels or orbitals have characteristic shapes which can be used to explain and predict the chemical bonds that atoms can form.

13. Orbital-
the region of space around the nucleus where an electron is likely to be found.

14. Energy level/energy shell-
the possible energies that electrons in an atom can have.

15. Three ways to show arrangements of electrons
Orbital Configuration Notation
Electron Configuration Notation
Electron Dot Notation

16. Electron configuration-
specific distribution of electrons in atomic orbitals of atoms or ions.

17. Valence shell-
the outside energy shell

18. Valence electrons-
an electron that is in the highest energy level of an atom.

19. Orbital Configuration Notation
each electron is assigned a space with an up spin or a down spin.
All up spins must be placed first.
Then place all down spins until all electrons are used.

20. Electron configuration notation:
is just the letters and numbers from the orbital configuration.
Example: Ar= 1s2 2s2 2p6 3s2 3p6

21. Electron dot notation:
the valence electrons represented by dots around the element symbol.
-fill in using the house memory trick

22. Hund’s Rule
every orbital in a subshell is singly occupied with one electron before any one orbital is doubly occupied, and all electrons in singly occupied orbitals have the same spin.

23. Aufbau Principle:
is used to determine the electron configuration of an atom, molecule or ion. The principle postulates a hypothetical process in which an atom is "built up" by progressively adding electrons.

24. Pauli’s Exclusion Principal
“no two electrons in the same atom can be in the same quantum state.” [1] This means that no two electrons can have the same set of quantum states of: 1) energy, 2) angular momentum magnitude, 3) angular momentum orientation, and 4) orientation of intrinsic spin.

25. Assessment LIST THE PERIOD TO WHICH EACH OF THE FOLLOWING BELONGS:
STRONTIUM: 5
IRON: 4
RADON: 6
ANTIMONY:
HOW MANY ELEMENTS ARE IN PERIOD 4? 18
HOW MANY ELEMENTS ARE IN PERIOD 6? 32

26. Assessment: NAME THE ELEMENT IN GROUP 3 PERIOD 4
Scandium.
HOW MANY VALENCE ELECTRONS ARE IN AN ATOM OF FLUORINE? 7
TO WHAT GROUP DOES CARBON BELONG 14