1. Chapter 6 The Periodic Table
Stylish Shoes
Mr Samaniego
Lawndale High School

2. What is in common with all the pictures below?

3. Which one does not belong?

4. Which one does not belong?

5. Which one does not belong?

6. Which one does not belong?

7. Section 6.1 - Organizing the Elements
The discovery of elements has been an ongoing process since ancient times
By the 1700’s, only about 13 elements had been identified
In the 1800’s, there were only 31 known elements
By 1865, that number had more than doubled to 65 known elements

9. History of the Periodic Table
In 1869, Dmitri Mendeleev published a classification scheme of all the currently known elements
Mendeleev insisted that elements with similar characteristics be listed in the same family
He also left blank spaces in his table for undiscovered elements

10. Mendeleev’s Periodic Table
Chemists used the properties of elements to sort them into groups (columns)
From 1829 to 1869, many other scientists proposed different systems, but none gained wide acceptance
In 1869, Dmitri Mendeleev arranged the elements in his periodic table in order of increasing atomic mass AND repeating properties

11. Mendeleev’s Periodic Table (1869)

12. Albert Tarantola’s Orbital Table
                                                                           

13. Timothy Stowe – Table for Physicists
                                                     

14. Theodor Benfey
                                                                           

15. Emil Zmaczynski
                                                       

16. Vocational Exile Periodic Table

17. The Periodic Law
About 40 years later, Henry Moseley determined atomic numbers for each known element so…
In the modern periodic table, elements are arranged in order of increasing atomic number
The Periodic Law states that when elements are arranged in order of increasing atomic number, there is a trend in their physical and chemical properties

18. Metals, Metalloids and Nonmetals (Red or Black “Ladder” on the periodic table aka zigzag line)
Elements can be grouped into three broad classes based on their general properties
Metals
Nonmetals
Metalloids

19. Metals: elements that are generally solid at room temperature, have a grayish color and shiny surface, and conduct heat and electricity

20. Nonmetals: elements that have varying properties but are generally poor conductors of heat and electricity

21. Metalloids: elements with some properties of metals and nonmetals

22. Section 6.2 - Classifying the Elements (Page 162-163)
The periodic table displays the symbols and names of the elements, along with information about the structure of their atoms (# of protons, neutrons and electrons)

23. Groups and Periods on the PT

24. Element that are solid at R. T
Element that are solid at R.T. are usually printed in black, liquid at R.T. printed in blue, and gases at R.T. are printed in green

25. Periodic Table at Different Temperatures

26. The 8 Groups of the Periodic Table
Hydrogen
Alkali Metals (Group 1A)
Alkaline Earth Metals (Group 2A)
Chalcogens (Group 6A)
Halogens (Group 7A)
Noble Gases (Group 8A)
Transition Metals (Group B)
Inner Transition Metals (Lanthanides and Actinides)

27. Practice Which group are the following elements in? Fluorine Calcium
Iron
Oxygen
Krypton
Lithium
Uranium
Hydrogen

29. Electron Configurations in Groups
Elements can be sorted into different groups based on their electron configuration
Noble Gases always have their s and p orbital completely filled with electrons, which makes them relatively inactive

30. Representative Elements
Representative Elements are Groups 1A through 7A because they display a wide range of physical and chemical properties

31. Section 6.3 – Periodic Trends
Properties of elements are related to their location on the periodic table
We will be studying 3 periodic trends:
Atomic Radius
Ionization Energy
Electronegativity

32. 1. Atomic Radius or Atomic Size
One-half the distance from center to center of two atoms
Atomic Radius

33. Atomic Radius or Atomic Size
What do you notice about the atomic radii of the elements on the periodic table?
Atomic Radius increases towards the bottom left corner of the PT

34. Atomic Radius/Size Practice
Which element has a greater atomic radius?
F or Cs
Ga or K
Kr or Rb
Ba or Si
Fr or W
O or Ag

35. Ions
Remember that neutral atoms have the same number of protons and electrons
When elements combine in compounds, they do not have the same number of protons and electrons anymore
Ions are atoms that have a positive or negative charge.

36. Positive and negative ions form when electrons are transferred between atoms (given up or stolen away)
Cations
Cation – an ion with a positive charge (lost electrons)

37. Anions
Anion – an ion with a negative charge (gained electrons)

38. Ionic Size
Cations are always smaller than the atoms from which they form
Anions are always larger than the atoms from which they form

39. Practice Which of the following is larger? Na or Na+ Al or Al3+
I or I-
Ca2+ or Ca
S or S2-
O2- or O

40. 2. Ionization Energy
The energy required to remove an electron from an atom

41. Ionization Energy
What trend do you notice about the ionization energy of the elements on the periodic table?
Ionization Energy increases towards the top right corner of the PT

42. Ionization Energy Practice
Which of these elements has a greater ionization energy?
Kr or Ar
Al or Na
S or Rb
Si or Cs
He or Ca
P or O

43. 3. Electronegativity
The ability of an atom to attract electrons to itself when in a compound

44. Electronegativity
What trend do you notice about the electronegativity of the elements on the periodic table?
Electronegativity increases towards the top right corner of the PT

45. Electronegativity Practice
Which element has greater electronegativity?
Na or F
Ca or C
Al or Mg
Sr or Al
Ca or K
Cl or F