Launch: 10/22   Grab your binder and immediately take a seat

  Answer the following two questions in complete sentences: 1.  Why do unstable isotopes go through radioactive

decay? 2.  How are nuclear reactions different from chemical

reactions?

What is a chemical bond? Mr. Heffner 10/22/09

What is a chemical bond?   Chemical bonds…

  hold atoms together to make compounds and molecules.

H H O

Chemical Bond

What is a chemical bond?

  Chemical bonds form during chemical reactions   Only the valence (outer) electrons are involved in

bonding!

What is a chemical bond?   Chemical bonds form during chemical reactions

  Bill Nye video   List 4 chemical reactions from the video.

  What gas was responsible for making our Pop Rockets pop?

Why do atoms form bonds?   Atoms form bonds…

  to become more stable.

  The most stable atoms are the noble gases   They have 8 valence electrons   All other atoms want to be like the noble gases

Why do atoms form bonds?   The octet rule is…

  oct- means 8   Like octagon & octopus

  that all atoms want to have 8 valence electrons

Foldable   Fold in half 3X, then fold in windows

  Key terms:   Chemical bond   Octet rule   Valence electrons (include the trick)

  Quiz your partner (2 min)

Practice Questions   Practice Questions Worksheet

  Answer in complete sentences!

Exit Slip 1.  Chemical bonds

a.  are always repulsive forces. b.  form between atoms to make compounds.

c.  are not found in certain molecules like H2S. d.  take a large amount of energy to form.

Exit Slip 2.  Which subatomic particles are responsible for

chemical bonding? a.  protons b.  electrons c.  valence electrons

d.  neutrons

Exit Slip 3.  Chemical bonds form because

a.  isotopes need to go through nuclear reactions to become more stable.

b.  electrons on one atom attract electrons on another. c.  atoms want to have electron configurations like the

halogens.

d.  atoms want to be stable and have a full valence ring.

Exit Slip 4.  The octet rule states that

a.  all atoms want to have 8 valence electrons. b.  all atoms want to have 18 valence electrons.

c.  the noble gases are the least stable atoms. d.  all atoms want to have 8 protons, 8 neutrons, and 8

electrons.

Exit Slip 5.  Which of the following atoms have a full octet?

a.  oxygen (O)

b.  iodine (I) c.  krypton (Kr)

d.  calcium (Ca)

Homework   Finish practice questions