1. Unit 4: The Periodic Table

2. Periodic Table
_______________ was the first person to find a way to list elements in order of increasing atomic mass

3. Periodic Table
He constructed the first periodic table in 1869, an arrangement of the elements according to similarities in their properties.

4. Mendeleev’s Periodic Table

5. Periodic Table
In 1913, ______ determined the atomic number of atoms and arranged the modern periodic table according to atomic number .

6. Modern Periodic Table
Each element is identified by its symbol placed in a square

7. Modern Periodic Table
The horizontal rows of the periodic table are called _____
There are ___

8. Modern Periodic Table
Each vertical column is called a ____ or ____
There are ____.

9. Periodic Table
A periodic law means that physical and chemical properties of elements are functions of their atomic numbers
Elements in the same group on the periodic table have similar properties

10. Modern Periodic Table
Group A elements are called the representative elements because they have a wide range of chemical and physical properties
Name the groups in Group A

11. Modern Periodic Table
Group B elements are called the ______________
The inner transition elements are the ______ and _____

12. Modern Periodic Table
The representative elements can be divided into three broad classes; Metals, Nonmetals, and Metalloids
What are some characteristics of each?

13. Classifying Elements by Electron Configuration

14. Practice: Write in shorthand and noble gas notation for: F, K, Co, Kr, Ce

15. Classifying Elements by Electron Configuration
Blocks on the periodic table - (s,p,d,f)
Group number equals the number of electrons in the outermost energy level

16. Classifying Elements by Electron Configuration
Each period number corresponds to the outermost principle energy level

18. Practice: Identify the block (s,p,d,f) of the periodic table that this element is located. A) Zinc B) Sodium C) Uranium D) Nitrogen

19. Periodic Trends

20. Coulomb’s Law
Forces of attraction between particles depend on charge of particles and distance between them
Higher charge = stronger attraction
Shorter distance = stronger attraction

21. Trend #1: Atomic Size
Measured by the radius of an atom via x-ray diffraction

22. Trend #1: Atomic Size - below is a graph of periodic table showing atomic size trends down a group and across a period

23. Trends in Atomic Size
Atomic size increases down a group because electrons are added to higher energy levels, which are further away from the nucleus. Since there is less of an attraction of the nucleus for the electrons, the atom is larger.

24. Trend #1: Atomic Size
Atomic size decreases across a period because within the same energy level, each element has one more p+ and e- than the preceding element. Therefore, outmost e’s are attracted more closely to the nucleus due to higher charge making it smaller.

25. Ion
Atoms with a charge
Cations – positive ions that lost electrons
Anions – negative ions that gained electrons

26. Ion
Predict the charge of the ion typically formed by the elements in groups 1-8 on the periodic table

27. Trend #2: Ionization Energy (IE)
IE is the energy required to overcome attraction to the nucleus and remove an electron from an atom.

28. Trend #2: Ionization Energy -graph of IE versus atomic number

29. Trend #2: Ionization Energy -graph of IE in groups and periods on the periodic table

30. Trend #2: Ionization Energy
Notice how the IE can be used to see charge of ion

31. Trend #2: Ionization Energy
IE decreases as you move down a group because the outermost electron is not as attracted to the nucleus because it is further away so it is easier to remove.

32. Trend #2: Ionization Energy
IE increases as you move left to right across a period because more p+ in the nucleus lead to greater attraction for the e- in the same energy level.

33. Trend #3: Ionic Size
Cations < Neutral < Anions
Consider the attraction of the nucleus for the outermost electrons to see why this is true

34. Trend #3: Ionic Size - table of ionic size and atomic size

35. Trend #3: Ionic Size
Ionic size increases down a group because the electrons are in energy levels further away from the nucleus and there is less attraction.

36. Trend #3: Ionic Size
Across a period ionic size of positive ions and negative ions decreases
But keep in mind that anions have bigger radii than cations.

37. Summary of Trends

38. Explain why a Mg atom is smaller than both Ca and Na atoms.
Review
Explain why a Mg atom is smaller than both Ca and Na atoms.

39. Review
Explain why a K atom has a smaller ionization energy than both Ca and Li atoms.

40. Review
The two ions K+ and Ca2+ each have 18 e-. Which would you expect to have a smaller radius? Justify your answer.

41. Review
Atomic size F I
IE F I
Ionic Size F I
EN F I
EA F I

42. Review
Atomic size Cs Ba
IE Cs Ba
Ionic Size Cs Ba
EN Cs Ba
EA Cs Ba