1. Periodic Table The Noble Gases
At the start of the 1890s, no one had any idea that there was a separate group of gases in the periodic table, the noble gases. Noble gases are familiar to us from their use in neon signs and helium balloons. By 1900 this whole new group had been identified and isolated. While trying to determine an accurate atomic mass for nitrogen, British physicist Lord Raleigh ( ) discovered that nitrogen prepared from ammonia was noticeably lighter than nitrogen that came from the atmosphere. He and William Ramsay ( ) both studied “atmospheric” nitrogen. By removing the nitrogen from it, they produced a tiny quantity of another gas. Since it did not react with anything they called it argon, from the Greek word for lazy. The discovery of helium followed a year later in Ramsay and his assistant Morris Travers ( ) then started to search for additional elements in this new group. They attempted this by fractional distillation of large quantities of liquid air and argon. In 1898, their efforts were rewarded; they had prepared krypton, neon, and xenon.
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 32
Kelter, Carr, Scott, Chemistry A Wolrd of Choices 1999, page 74

2. Guiding Questions Why is the periodic table so important?
Why is the periodic table shaped the way it's shaped?
Why do elements combine? Why do elements react?
What other patterns are there in the world and how do
they help us?
Periodic Table Study Questions
1.         Why did chemists make the periodic table?
2.         Why was the table difficult to make?
3.         Why were Dobereiner’s triads of limited use at a periodic table?
4.         What did Newland discover about the elements?
5.         What did Meyer contribute to the development of the periodic table?
6.         What did Mendeleev use as the organizing property for the periodic table?
7.         What problem developed from the use of this property?
8.         What is common to elements in a column of the table?
9.         How did properties change in a row of the table?
10.       What was the significance of gaps in Mendeleev’s periodic table?
11.       What did Moseley use to order the elements in the periodic table?
12.       How did Moseley change the periodic law?
13.       What determines the identity of an element?
14.       Why do elements in a column of the periodic table have similar properties?
15.       With respect to the Periodic Table, what is the meaning of periodic?
16.       What does a row of the Periodic table represent?
17.       What happens to valence electrons as you move left to right in a row?
18.       When determines stability in an atom?
19.       List, from least to most, the stable configurations in an atom.
20.       What determines the column of the periodic table an element is in?
21.       What sublevels are in the outer level of an atom?
22.       What is the maximum number of electrons in the outer level of an atom?
23.       What determines the row and column of the periodic table an element is in?
24.       What are common properties of metals?
25.       What are common properties of non-metals?
26.       What three things can happen to electrons when atoms form compounds?
27.       The configuration of He is 1s2, but it is placed in column 18. Explain this discrepancy.
28.       Hydrogen is obviously not an alkali metal. Why is it in column 1 of the table?
29.       What is necessary for a metalloid to act as a semiconductor?

3. Table of Contents ‘Periodic Table’
How to Organize Elements
Mendeleev’s Periodic Table
Modern Periodic Table
Groups of Elements
Metals, Nonmetals, Metalloids
Discovering Elements
Origin of Names of Elements
Selected Elements
Electron Filling Order
Diatomic Molecules
Size of Atoms – Trends
Ionization Energy
Summary of Periodic Trends
Essential Elements
Element Project
When elements are listed in order according to the number of protons, repeating patterns of physical and chemical properties result and can be used to make predictions
The ability to create a model and then make predictions that prove to be correct, based upon that model, is what science is all about.
More Specifically...:
History
Describe the contributions of Mendeleev and Mosley on the periodic table
a. periodic table by atomic mass and property - Dimitri Mendeleev
b. periodic table by atomic number - Henry Moseley
Trends - Physical Properties
Associate rows with periods and columns with families or groups.
Identify the seven diatomic gases
Give locations and list characteristic properties of metals, non-metals, metalloids, and noble gases.
Label the following areas on a periodic chart
a. Alkali metals
b. Alkaline Earth Metals
c. Transition Metals
d. Metalloids
e. Halogens
f. Noble gases
g. Lanthanides
h. Actinides
Trends - Chemical Properties
Define and give the general trends on the periodic table for
a. Ionization energy
b. Electronegativity
c. Atomic radius / Ion radius
d. Electron affinity
e. Reactivity
Define shielding effect and use it to explain trends in families
Define effective nuclear charge and use it to explain trends in periods
Predict location on periodic table given ionization energy data
State that the noble gas configuration is the most stable electron configuration
Predict oxidation states for various elements based on their proximity to a noble gas in the periodic table
Write electron configurations and orbital diagrams of ions

4. Atomic Structure and Periodicity
You should be able to
Identify characteristics of and perform calculations with frequency and
wavelength.
Know the relationship between types of electromagnetic radiation and
Energy; for example, gamma rays are the most damaging.
Know what exhibits continuous and line spectra.
Know what each of the four quantum numbers n, l, m, and ms represents.
Identify the four quantum numbers for an electron in an atom.
Write complete and shorthand electron configurations as well as orbital
diagrams for an atom or ion of an element.
Identify the number and location of the valence electrons in an atom.
Apply the trends in atomic properties such as atomic radii, ionization
energy, electronegativity, electron affinity, and ionic size.
Fast Track to a 5 (page 61)
OBJECTIVES:
To become familiar with the history of the periodic table
To understand periodic trends in atomic radii
To be able to predict relative ionic sizes within an isoelectronic series
To correlate ionization energies and electron affinities with the chemistry of the elements
To become familiar with the relationship between the electronegativity of an element and its chemistry
To understand the correlation between the chemical properties and the reactivity of the elements and their positions in the periodic table
To be able to describe some of the roles of trace elements in biological systems
Periodic Properties -Study Questions
1. What 4 things determine how properties change?
2. What two properties determine the reaction tendency of an element?
3. What is atomic radius?
4. What are the patterns for atomic radius in the periodic table?
5. What two factors determine the force felt by the outer electrons?
6. What is the shielding effect?
7. What two factors cause atomic radius to increase in the elements of a column?
8. What causes the atomic radius to decrease across a row?
9. Why are the noble gas atoms larger than expected?
10. What configuration is found in ions?
11. Why is a positive ion smaller than its atom?
12. Why is a negative ion larger than its atom?
13. What is an oxidation number?
14. What is the pattern for oxidation numbers?
15. What property determines the reactivity of the metals?
16. What property determines the reactivity of the non-metals?
17. What is ionization energy?
18. What factors affect ionization energy?
19. What are the patterns for ionization energy in the periodic table?
20. Why do these patterns form?
21. Why are second and higher ionization energies higher?
22. Why do the alkali metals react violently with H2O?
23. Why are the alkaline earth metals less reactive than the alkali metals?
24. What is electron affinity?
25. What factors influence electron affinity?
26. Why does electron affinity drop down a column?
27. What happens to electron affinity across a row and why?
28. Explain why Be, N, and Ne are exceptions to the trends.
29. Why does ionization energy have the greatest effect on the reactivity of metals?
30. Why does electron affinity have the greatest effect on the reactivity of non-metals?

5. > Potassium atom = [Ar]4s1 Calcium atom = [Ar]4s2 p = 19 n = 20
e = 19
p = 20
n = 20
e = 20
K  e K1+
Ca  2 e Ca2+
Potassium ion = K1+ ≡ [Ar]
1s22s22p63s23p6
Calcium ion = Ca2+ ≡ [Ar] or
1s22s22p63s23p6
19e-
18e-
>
20e-
18e-
19+
20+

6. < Oxygen atom = [He]2s22p4 Fluorine atom = [He] 2s22p5 p = 8 n = 8
O e-  O2-
F + e-  F1-
Oxide ion
Oxygen ion = O2- ≡ [Ne]
1s22s22p6
Fluoride ion
Fluorine ion = F1- ≡ [Ne]
1s22s22p6
8 e-
6 e-
<
7 e-
8 e- 8+ 9+

7. Energy Level Diagram of a Many-Electron Atom
6s p d f 32
5s p d 18
4s p d
Arbitrary
Energy Scale 18
3s p 8
Original reference: Pimental, Chemistry An Experimental Science, (CHEM Study), 1969, page 266.
2s p 8 1s 2
NUCLEUS
O’Connor, Davis, MacNab, McClellan, CHEMISTRY Experiments and Principles 1982, page 177