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Heather Mellows’ Lesson. Summer workshop on Directed Discourse Approach. This lesson introduces types of bonds, unit 3, high school chemistry. The element cards are found at the end. Two copies of each card, cut up and passed out to students at the beginning of the lesson.
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Heather Mellows’ Lesson Summer workshop on Directed Discourse Approach. This lesson introduces types of bonds, unit 3, high school chemistry. The element cards are found at the end. Two copies of each card, cut up and passed out to students at the beginning of the lesson. The table of electronegativity used is also given at the end.
Warm up 10-12 What factors change between elements across the periodic table? What factors change between elements down a column of the periodic table? (Be specific, listing both physical and chemical properties)
Who Has the Electrons? One thing that changes across and down the PT is the attractiveness of atoms for electrons. Not physical attractiveness, but positive and negatives. Na
Atoms on the right of the PT are very attractive to electrons. They get a high rating, up to a score of 4.0. Atoms on the left of the PT are not very attractive to electrons. They get a lower rating, down to 0.7.
Making Bonds Activity Poof! You have been transformed into an atom of an element. Your attractiveness to electrons is written on your card. C Carbon 2.5 Carbon is somewhat attractive to electrons.
Task #1 Find someone that is equally attractive to electrons and stand next to them. What do you notice about them? If you had two electrons between you, which of you is more attractive to the electrons? If this was a tug of war, who would win? If the electrons where the tie on the rope, where would the be? F 4.0 F 4.0
Task #2 Find someone a little bit more or less attractive to electrons and stand next to them. What do you notice about them? If you had two electrons between you, which of you is more attractive to the electrons? If this was a tug of war, who would win? If the electrons where the tie on the rope, where would the be? F 4.0 Cl 3.5
Task #3 Find someone a lot more or less attractive to electrons and stand next to them. What do you notice about them? If you had two electrons between you, which of you is more attractive to the electrons? If this was a tug of war, who would win? If the electrons where the tie on the rope, where would the be? Na 1.3 Cl 3.5
Practice Given each of these pairs of atoms, who has the electrons? 2.5 C H 2.1 1.7 Hg Cl 3.5 2.1 P P 2.1 0.9 K Br 2.8 3.5 O S 2.5 Look at the chart at your table for the values for each element. : : : : :
Vocabulary 17) electronegativity: the amount of attractiveness an atom has for electrons C Carbon 2.5 Electronegativity
Vocabulary 18) Covalent bond: electrons are shared equally between atoms of very similar electronegativity F 4.0 F 4.0
Vocabulary 19) Polar covalent bond: electrons are shared unequally between atom of somewhat similar electronegativity F 4.0 Cl 3.5
20) Ionic: electrons are transferred from one atom to another creating a positive an negative ion that are then electrostatically attracted. Na 1.3 Cl 3.5
Practice Given each of these pairs of atoms, what type of bond is present? 2.5 C H 2.1 covalent 1.7 Hg Cl 3.0 very polar covalent 2.1 P P 2.1 covalent 0.9 K Br 2.8 ionic 3.5 O S 2.5 polar covelent : : : : :
