1. Chapters 4.3 & 5.1-3 Notes A. Atomic Review
B. Ch. 4.3: Modern Atomic Theory
C. Ch. 5.1: Organizing the Elements
D. Ch. 5.2: The Modern Periodic Table
E. Ch 5.3: Representative Groups

2. A. Models of the Atom, pg
1803 – Dalton Model: pictures atoms as tiny, indestructible particles, with no internal structure 1897 – Thomson: discovers e-, leading to his “plum-pudding” model. He pictures e- embedded in a sphere of positive electric charge 1911 – Rutherford: states that atom has a dense, positively charged nucleus. E- move randomly in the space around the nucleus 1913 – Bohr: e- move in spherical orbits at fixed distances from the nucleus 1926 – Electron Cloud: more dense where electron is likely to be

3. A. Atomic Review Subatomic particles (p, n, e) Symbols Atomic # Mass #
Isotopes

4. Diagram of an atom p – Proton e – Electron n - Neutron Proton Quark
Nucleus
What do you now know about the location of electrons?
Neutron
p – Proton
e – Electron
n - Neutron
Electron

5. B. Ch. 4.3: Modern Atomic Theory
Energy levels: the possible energies that electrons in an atom can have (staircase analogy)
Electron Cloud: visual model of the most likely locations for electrons in an atom (windmill analogy)
Orbital: a region of space around the nucleus where an electron is likely to be found (map of dots analogy)
The most stable electron configuration is when electrons are in orbitals with the lowest possible energies.

6. Energy Levels Outer level electrons have more energy.
Different levels hold different numbers of electrons.

7. Energy Level 3
18 electrons
Energy Level 2
8 electrons
Energy Level 1
2 electrons
Nucleus

8. C. Ch 5.1: Organizing the Elements
How did Mendeleev use solitaire to help him organize 63 elements?
Compare and contrast Mendeleev’s periodic table to the table we use today.
Mendeleev arranged elements by increasing atomic mass
Today elements are arranged by increasing atomic number and changes in physical and chemical properties.

9. D. Ch. 5.2: The Modern Periodic Table
What information can we get from the table without prior knowledge?
Solids, liquids, gases, not found in nature, metals, nonmetals, metalloids…
**NOTICE THE BOTTOM
Lanthanide series and Actinide series
Lanthanide can be found naturally on Earth, while the Actinide series only has some found in nature. The rest are made in labs only. All Actinide are radioactive.
Characteristics of metals, nonmetals, and metalloids?
Metals: hard, dense, high melting point, shiny, malleable, ductile, reactive, 88 elements to left of stairstep are metals or metal like, alloys (mixing of metals), corrosion
Nonmetals: dull, brittle, not ductile or malleable, low density, low melting point, poor conductors, form compounds with each other
Metalloids: characteristics of both, solids, shiny or dull, ductile, malleable, conductors (not well but can), semiconductors (conducts at high temps but not at low temps)

10. Families (Groups) and Periods (Rows)
Ended here

11. Group or Family Trends Up and down; columns
Elements in the same group have similar properties (have same # of valence electrons).
Group 1, very reactive (only 1 valence electron)
Group 8A, not very reactive (has all 8 valence electrons)
Alkali metal, alkaline earth metal, halogens, noble gases…
Start here 1/8

12. Row or Period Trends
As you go to the right, you add 1 proton and 1 electron.
The row ends when there are 8 electrons in the outer energy level
Increasing Energy Levels

13. Variation Across a Period
From left to right, the elements become less metallic and more nonmetallic in their properties. Na – reacts quickly and violently with water Mg – reacts with hot water Al – doesn’t react with water, but reacts w/oxygen Si – least reactive (except Ar) P & S – normally don’t react w/water, but react w/O and Cl, which is a highly reactive nonmetal. Ar – hardly reacts at all

14. SOME TRENDS OF THE PERIODIC TABLE
We won’t work with all of these…

15. Periodic Table Trends
Electronegativity – measure of attraction for electrons
Ex: High electronegativity = strong attraction
Ionization energy – energy required to remove an electron
Ex: Low ionization E = easy to remove electron
Electron affinity – ability of an atom to accept an electron
Ex: High electron affinity = good at accepting e-
Metallic character – same as atomic radii trend
*Atomic radius – see next slide
* Reactivity
*Oxidation numbers – shows # of e- gained or lost
*Valence electrons – see group number
*Energy levels – see row number (* = characteristics you need to know)

16. Atomic Radii Pattern

17. Reason for atomic radii pattern?
As you move down a group, the radii increases…
The number of energy levels increases, and each subsequent energy level is further from the nucleus than the last
As you move across a row, the radii decreases…
More electrons are added to the same energy level, and more protons are added to the nucleus. Thus, there is a stronger force of attraction pulling the electrons closer to the nucleus.
End here 1/6/16 Wednesday

18. How to draw an Electron Dot Diagram
Find element on table.
Write symbol.
Look at the group number to determine the number of dots.
Draw dots.
Book discusses this in Chapter 6.1
Start here 1/7/16 Thursday

19. Electron Dot Diagrams Aka lewis dot structure
Write steps explaining how to draw a Lewis Dot Structure.

20. E. Ch. 5.3: Representative Groups
Valence Electron – electron that is in the highest occupied energy level of an atom (outermost energy level)
Elements in a group have similar properties because they have the same number of valence e-
The number of valence electrons help us predict how atoms will interact with each other (bonding).

21. Representative Groups, cont.
Group 1A – Alkali Metals
1 valence electron, very reactive
Group 2A – Alkaline Earth Metals
2 valence electrons, harder than alkali
Group 4A – Carbon Family
4 valence electrons, metal, nonmetal, metalloid
Group 5A – Nitrogen Family
5 valence electrons
Group 6A – Oxygen Family
6 valence electrons
Group 7A – Halogens
7 valence electrons, highly reactive nonmetals
Group 8A – Noble Gases
8 valence electrons, colorless, odorless, unreactive