Launch   Grab your binder and immediately take a seat

  Take out last night’s homework

1.  From memory, sketch out the periodic table and label the 5 families.

2.  What family do the following belong to? i.  Sr ii.  I

iii.  Fr iv.  Xe

Weekly Schedule   Monday: Atomic Radius

  Tuesday: Electronegativity & Ionization Energy

  Wednesday: Metals, nonmetals, special groups

  Thursday: Atomic structure & nuclear processes

  Friday: Mid-Term Exam   Only excused absences, otherwise 0!   No retakes!

We don’t have much time!

If you don’t understand something, ask!

Review Session Today   During lunch

  After school (until 4:30pm)

How is the atom structured?

Mr. Heffner 10/15/09

How is the atom structured?

0

0

0

0 Nucleus

Rings • Protons (1 amu) • Neutrons (1 amu) • Electrons (0 amu)

valence = outermost

How is the atom structured?   Density comparison:

  The nucleus   Large mass   Small volume   Dense!

  The rings   Small mass   Large volume   Not Dense!

How is the atom structured?

Atomic number 5

B Boron 10.81 Atomic

mass

Really important!

Example #1 How many protons, neutrons, and electrons does an atom

of nitrogen have?

  Step 1: Find the # of protons   Atomic number

  Step 2: Find the # of neutrons   Atomic mass – atomic number

  Step 3: Find the # of electrons   Same as # of protons

7

14 - 7 =

7

7

What about valence electrons?

Example #2 How many protons, neutrons, and electrons does an atom

of nitrogen-15 have?

  # of protons   Atomic number

  # of neutrons   Atomic mass – atomic number

  # of electrons   Same as # of protons

7

15 - 7 =

7

8

Isotope: different # of neutrons

Nuclear Review   Two forces in the nucleus:

  Strong force: holds the nucleus together   “Bungees”

  Electrostatic repulsive force: tries to break it apart   Protons fighting

  There are three types of radioactive decay:   Alpha (α) decay

  Beta (β) decay   Gamma (γ) decay

Practice Questions   Review Worksheet #4

Notecard   One notecard, front and back

  Things I would include:   Definitions: isotope, atomic number, alpha particle,

valence electron, density of nucleus…   Pictures of the trends

  Families on the periodic table

Homework   Make a notecard

  Finish Review Worksheet #4

  Study hard!   Review your notes

  Check out our exit slips online!