Launch: 9/22 2.  The number of _________________, not _________________

or _________________, determines the unique properties of an element.

a.  protons; neutrons; electrons b.  neutrons; protons; electrons c.  neutrons; protons; ions d.  electrons; protons; neutrons

3.  Atomic mass is the sum of the a.  protons and electrons in an atom. b.  protons and neutrons in an atom. c.  neutrons and electrons in an atom. d.  particles in the rings.

What are groups and periods?

Mr. Heffner 9/22/09

Review

What are periods?

I.  Periods: rows (left to right)

What are groups?

I.  Groups: columns (top to bottom)

What are groups A.  Similar properties because same number of

valence electrons

1.  Elements of the same group have the same chemical properties

i.  They have the same number of valence electrons

ii.  Valence electrons determine reactive properties

Groups 2.  Easy trick: look at the group number

i.  Lithium (Li) is in Group 1 = 1 valence electron

ii.  Oxygen (O) is in Group 16 = 6 valence electrons

B. Special Metal Groups 1.  Alkali metals: Group 1

i.  1 valence electron

ii.  Example: sodium (Na)

iii.  Soft, white and extremely reactive

Alkali Metals

B. Special Metal Groups 2.  Alkaline earth metals: Group 2

i.  2 valence electrons

ii.  Example: magnesium (Mg)

Alkaline Earth Metals

B. Special Metal Groups 3.  Transition metals: Groups 3-12

i.  Varying numbers of valence electrons

ii.  Example: iron (Fe)

Transition Metals

C. Special Nonmetal Groups 1.  Halogens: Group 17

i.  7 valence electrons ii.  Example: fluorine (F)

Halogens

C. Special Nonmetal Groups 1.  Noble gases: Group 18

i.  8 valence electrons ii.  Example: neon (N)

Noble Gases

Summary

Practice Questions 1.  On the periodic table, groups are ______ and periods are

______.

2.  What two things do all elements of the same group have in common?

3.  How many valence electrons does C, F, H, O, N, and Li have?

4.  List three different elements that would have similar properties to Mg.

5.  Would you expect Cu to have similar properties to Zn? Why or why not?

Homework   Textbook

  Pg. 122 Section Review #7, 12, 13   Pg. 131 Section Review #1, 3, 5, 7

  Quiz Corrections

  Start reviewing for Monday’s Unit #2 Exam!

Exit Slip 1.  The columns of the periodic table are called

a.  groups. b.  periods.

c.  metals. d.  semimetals.

Exit Slip 2.  The region highlighted below represents the

a.  noble gases. b.  halogens.

c.  alkali metals. d.  semimetals.

Exit Slip 3.  Chlorine (Cl) is an example of a(n)

a.  alkali metal and has 2 valence electrons. b.  alkali metal and has 1 valence electron.

c.  halogen and has 7 valence electrons. d.  noble gas and has 8 valence electrons.

4.  Which of the following has similar chemical properties to those of Calcium (Ca)?

a.  gold (Au) b.  sodium (Na)

c.  aluminum (Al) d.  magnesium (Mg)

Exit Slip 5.  The alkali metals have

a.  one valence electron, are unreactive, and are located on the far right side of the periodic table.

b.  one valence electron, are extremely reactive, and are located on the far left side of the periodic table.

c.  two valence electrons, are extremely reactive, and are located on the far left side of the periodic table.

d.  none of the above.

Quiz Corrections   Take out a new piece of binder paper and label

“Quiz Corrections”

  For each question your got wrong   Copy the question

  Write out the correct answer   Explain why your answer was wrong