1. Chemistry 1 Notes #10 Chapter 6 Modern Periodic Table
Last Updated November 16, 2018

2. Antoine Lavoisier Late 1790s French Scientists
Compiled a list of elements
Only 23 elements known at the time

3. John Newlands 1864 English Chemist
Proposed an organization scheme for the elements based on increasing atomic mass noting that properties repeated every eighth element.
Idea did not work for all elements

4. Meyer and Mendeleev Meyer-German Chemist Mendeleev-Russian Chemist
Mendeleev published his organization scheme first and is therefore given more credit.

5. Mendeleev Continued
Mendeleev arranged elements according to increasing atomic masses but into columns with similar properties
Was able to predict the properties of yet undiscovered elements

6. Not entirely accurate as new elements were discovered and atomic masses of known elements were more accurately determined.

7. Henry Mosley 1913 English Chemist
Arranged elements according to increasing atomic number
Resulted in clear Periodic Patterns

8. Periodic Law
The periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number

9. Review/Discuss Groups – Columns Periods – Rows
Main Block Elements (Groups 1A-8A or 1-2,13-18)
Transition Elements (Groups 1B-8B or 3-12)
1-18 Newer numbering system for groups

10. Review/Discuss Continued
Metals
Non-metals
Metalloids
Transition
Inner Transition
Alkali-metals
Alkaline Earth Metals
Halogens
Noble Gases

12. Classification of the elements
Valence e- and the Periodic Table
See Figure 6-9 page 160

13. Blocks s p d f
Know the location of each block

14. Periodic Trends Atomic Radius  in picometers (1 x 10-12 meters)
Generally Decreases from left to right and increases as you move down the periodic table

16. Ion Charged Particle due to loss gain or sharing of electrons
Loss of electrons = smaller radius
Gain of electrons = larger radius
Compare Trends from Fig 6-11 pg 163 to Fig 6-14 pg. 166
Lost e- are generally valence e-

17. Ions Continued Across Periods moving left to right
+ ions decrease in size
Ions decrease in size
Down Groups Both + and – ions increase radii

18. Ionization Energy- Energy required to remove an e- from a gaseous atom
First ionization energy = 1 e- to remove
Ionization Energy can be thought of as how strongly an atom’s nucleus holds on to its valence e-

19. Atoms with large ionization energy are less likely to form + ions
Low ionization energy indicates an atom loses e- easily likely to form + ions

21. Octet Rule- atoms tend to lose, gain or share e- in order to acquire a full set of eight valence e-
Electronegativity- ability of an atom to attract e- to itself in a chemical bond
Units are arbitrary and are called Paulings, for Linus Pauling

22. Electronegativity decrease as you move down a group and increases as you move left to right
Lowest electronegative = lower left
Highest electronegative = upper right