Launch   Grab your binder and immediately take a seat

  Answer the following questions:

1.  Using arrows, draw the trend for atomic radius.

2.  Which atoms below have a larger atomic radius than aluminum (Al)?

i)  Cl iii) Si v) Na

ii) B iv) He vi) Ca

Weekly Schedule   Monday: Atomic Radius

  Tuesday: Electronegativity & Ionization Energy

  Wednesday: Metals, nonmetals, special groups

  Thursday: Atomic structure & nuclear processes

  Friday: Mid-Term Exam

We don’t have much time!

If you don’t understand something, ask!

What is the trend in ionization energy/electronegativity?

Mr. Heffner 10/13/09

Ionization Energy   Ionization energy is…

  how much energy it takes to steal an electron

Electronegativity   Electronegativity is…

  how good an atom is at stealing electrons

Ionization Energy/Electronegativity

  The trend: 1.  IE/E increases across a period (LR)

2.  IE/E decreases down a group (Top Bottom)

Dec

reas

es

Increases

Example #1 Which has higher amount of ionization energy,

oxygen (O) or carbon (C)?

  Step #1: Find the elements

Example Which has higher amount of ionization energy,

oxygen (O) or carbon (C)?

  Step #2: Look at the keywords

Which has a higher amount of ionization energy,

oxygen (O) or carbon (C)?

Example Which has higher amount of ionization energy,

oxygen (O) or carbon (C)?

  Step #3: Identify which is closest to He

Example Which is less electronegative,

Beryllium (Be) or potassium (K)?

  Step #1: Find the elements

Example Which is less electronegative,

Beryllium (Be) or potassium (K)?

  Step #2: Look at the keyword

Which is less electronegative,

Beryllium (Be) or potassium (K)?

Example Which is less electronegative,

Beryllium (Be) or potassium (K)?

  Step #3: Identify which is closest to Fr

Practice Questions   Review Worksheet #2

  Use the 3-step method!

Ionization Energy/Electronegativity

  The trend: 1.  IE/E increases across a period (LR)

2.  IE/E decreases down a group (Top Bottom)

Dec

reas

es

Increases

Atomic Radius   The trend:

1.  Atomic radius decreases across a period (LR)

2.  Atomic radius increases down a group (Top Bottom)

Incr

ease

s

Decreases

Exit Slip 1. Which of the following atoms has the largest

atomic radius? a. oxygen (O) b. phosphorus (P) c. sulfur (S)

d. chlorine (Cl)

Exit Slip 2. In general, how does ionization energy vary

throughout the periodic table? a. it decreases across a period from left to right, and

decreases down a group from top to bottom b. it increases across a period from left to right, and

increases down a group from top to bottom c. it increases across a period from left to right, and

decreases down a group from top to bottom d. It decreases across a period from left to right, and

increases down a group from top to bottom

Exit Slip 3. Which of the following atoms has the smallest first

ionization energy? a. lithium (Li) b. beryllium (Be) c. sodium (Na)

d. potassium (K)

Exit Slip 4. Electronegativity is the

a. energy it takes to remove an electron from an atom. b. number of protons and neutrons in an atom.

c. measure of how good an atom is at stealing electrons.

d. distance from the nucleus to the valence ring.

Exit Slip 5.  Which of the following correctly lists the elements

in order of increasing electronegativity (least to most)?

a.  O < P < Al < Na

b.  Na < Al < P < O c.  P < O < Na < Al

d.  Al < P < O < Na

Homework   Finish Review Worksheet #2

  Make a mind map – double points!   In center oval: “periodic trends”   In 3 ovals around:

  “atomic radius”

  “electronegativity”

  “ionization energy”

  In 3 boxes for each:   definition of term

  trend

  picture