1. Anatomy of the Periodic Table
Chem-To-Go Lesson 10
Unit 3
You might want to have a periodic table handy during the video!

2. Quick History Henry Moseley Dmitri Mendeleev
“Father of the Periodic Table”
Henry Moseley
Arranged the elements in order of increasing atomic mass
Arranged the elements in order of increasing atomic number

3. Periodic Law
Periodic Law - The periodic law states that certain chemical and physical properties repeat themselves every eight elements when the elements are arranged in order of increasing atomic number.
Periods = rows
Columns = groups

4. Major Classifications
Metals
Nonmetals
Metalloids

5. Properties Metals Nonmetals
Diverse in room temperature state of matter
Non-conductors
Brittle
Non-lustrous
Gain electrons to become stable
Typically solid at room temperature
Conduct electricity and heat
Shiny
Malleable
Ductile
Lose electrons to be stable

6. Six Important groups

7. Two important patterns
Number of Valence Electrons = Column Number

8. Two important patterns
Common Charge of the Ion Pattern

9. Atomic Radius & ionic radius
Chem-To-Go Lesson 11
Unit 3

10. trends Trend = a repeating pattern
Periodic Trend = a repeating pattern on the periodic table

11. Atomic radius
Definition: ½ the distance between the nuclei of two identical touching atoms

12. Atomic radius
Period trend: [row pattern]; atomic radius DECREASES from left to right across a row
PERIOD TREND
Group trend: [column pattern]; atomic radius DECREASES from bottom to top of a column
GROUP TREND
WHY?
Radius decreases across a period because the nucleus is gaining more protons to become larger and more strongly positive. The electron cloud is drawn in by forces of attraction.
Radius decreases up a group because there are fewer energy levels at the top of the periodic table.

13. SAMPLE MULTIPLE CHOICE:
Atomic radius
Memory Tool
Use a periodic table!
Find all of the elements.
Apply the trend.
SAMPLE MULTIPLE CHOICE:
Which of the following atoms will has the smallest radius?
a. Tin b. Strontium c. Selenium d. Arsenic

15. SAMPLE MULTIPLE CHOICE:
Atomic radius
Memory Tool
Use a periodic table!
Find all of the elements.
Apply the trend.
SAMPLE MULTIPLE CHOICE:
2. Which of the following atoms will has a larger radius than calcium?
Aluminum b. Copper c. Potassium d. None

16. Ions
Cation= Positively charged ion (neutral atom has lost one or more electrons)
Anion= Negatively charged ion (neutral atom has gained one or more electrons)

17. ionic radius
Definition: size of the ion; usually compared to the size of its neutral atom

18. ionic radius CATION RADIUS ANION RADIUS
Cations form by losing electrons. As electrons are lost, the ion becomes smaller.
Anions form by gaining electrons. As electrons are gained, the ion becomes larger.

19. Ionization Energy & Electronegativity
Chem-To-Go Lesson 12
Unit 3

20. 1st Ionization Energy
Definition: the energy required to remove a first electron from an atom

21. 1st Ionization Energy

22. 1st Ionization energy WHY?
Period trend: [row pattern]; ionization energy INCREASES from left to right across a row
PERIOD TREND
Group trend: [column pattern]; ionization energy INCREASES from bottom to top of a column
GROUP TREND
WHY?
The energy needed to remove an electron increases as the nucleus becomes more strongly positive and the electrons are drawn in closer to it.
The energy needed to remove an electron increases as the valence electrons are closer to the nucleus. The shielding effect makes removing electrons easier from higher energy levels.

23. SHIELDING EFFECT OF CORE ELECTRONS
1st Ionization energy
SHIELDING EFFECT OF CORE ELECTRONS
The energy needed to remove an electron increases as the valence electrons are closer to the nucleus. The shielding effect makes removing electrons easier from higher energy levels.

24. SAMPLE MULTIPLE CHOICE:
1ST Ionization Energy
Memory Tool
Use a periodic table!
Find all of the elements.
Apply the trend.
SAMPLE MULTIPLE CHOICE:
Which of the following atoms will has the smallest ionization energy?
a. Tin b. Strontium c. Selenium d. Arsenic

25. SAMPLE MULTIPLE CHOICE:
1st Ionization Energy
Memory Tool
Use a periodic table!
Find all of the elements.
Apply the trend.
SAMPLE MULTIPLE CHOICE:
2. Which of the following atoms has a larger ionization energy than calcium?
Aluminum b. Copper c. Potassium d. None

26. Electronegativity
Definition: the ability of an atom in a chemical bond to draw the bonding electrons closer to itself

27. Electronegativity
Notice that the noble gases are NOT in the image. Since they don’t form bonds, they have no electronegativity values.

28. Electronegativity WHY?
Period trend: [row pattern]; electronegativity INCREASES from left to right across a row
PERIOD TREND
Group trend: [column pattern]; electronegativity INCREASES from bottom to top of a column
GROUP TREND
WHY?
The larger and more positive nuclei on the right side of the table are more likely to attract the bonding electrons
An unshielded nucleus is better at attracting bonding electrons. Fewer energy levels means more electronegativity.

29. SAMPLE MULTIPLE CHOICE:
Electronegativity
Memory Tool
Use a periodic table!
Find all of the elements.
Apply the trend.
SAMPLE MULTIPLE CHOICE:
Which of the following atoms will has the highest electronegativity?
a. Tin b. Chlorine c. Neon d. Arsenic

30. SAMPLE MULTIPLE CHOICE:
Electronegativity
Memory Tool
Use a periodic table!
Find all of the elements.
Apply the trend.
SAMPLE MULTIPLE CHOICE:
2. Which of the following atoms will has a higher electronegativity than P?
Oxygen b. Fluorine c. Helium d. None

31. Electron Affinity
Definition: the amount of energy released when an electron is added to a neutral atom or molecule to form a negative ion.
Period trend: [row pattern]; electron affinity INCREASES from left to right across a row
PERIOD TREND
Group trend: [column pattern]; electron affinity INCREASES from bottom to top of a column

32. Electron Affinity
Memory Tool