Unit 6: Chemical Bonds
Reading
BJU Chemistry book: Ch. 6 "Chemical Bonds"
AP: Zumdahl Chemistry Ch. 8 "Bonding General Concepts" and (optional reading) Ch. 9 "Covalent Bonding"
AP Princeton Guide: Unit 2
Topics
Lab
BJU Chemistry book: Ch. 6 "Chemical Bonds"
AP: Zumdahl Chemistry Ch. 8 "Bonding General Concepts" and (optional reading) Ch. 9 "Covalent Bonding"
AP Princeton Guide: Unit 2
Topics
- Covalent bonds
- Ionic bonds
- Metallic bonds
- Lewis diagrams
- Polyatomic ions
Lab
- Nitrogen Compounds lab
Below: Covalent bonding of two chlorine atoms. Once bonded, they both share 8 valence electrons. This is called an "octet". This forms a strong bond which is not easily broken. The two atoms have become a molecule of chlorine.
Below: Ionic bonding of a sodium atom (Na) and a fluorine (F) atom. The sodium entirely gives up its outer valence electron so that both atoms now have 8 valence electrons. As a result of this electron transfer, sodium now becomes a "cation" with a +1 charge, and fluorine becomes an "anion" with a -1 charge. Since positive and negative charges attract one another, the two ions bond together in an 'ionic bond'. If this is carried out in water (aqueous solution) they stay apart from one another. If the water is evaporated, they form a crystal in the bottom of the beaker. We discuss "solutions" later in the course...
Lecture outline
Chemical bonds are formed by lowering the total energy of the constituent atoms. Putting it another way, two compounds will "react" if the resulting compound(s) are more stable.... i.e. in a more stable energy configuration. Covalent bonds form when the outer electrons of atoms are "shared", while Ionic bonds form when outer electrons are "transferred" or "stolen".
Nitrogen Compounds lab
We will make and test various nitrogen compounds.
Chemical bonds are formed by lowering the total energy of the constituent atoms. Putting it another way, two compounds will "react" if the resulting compound(s) are more stable.... i.e. in a more stable energy configuration. Covalent bonds form when the outer electrons of atoms are "shared", while Ionic bonds form when outer electrons are "transferred" or "stolen".
Nitrogen Compounds lab
We will make and test various nitrogen compounds.
- Nitrogen (N2) is the most prevalent element in "air", making up 78% of the earth's atmosphere.
- Nitrogen is the "lazy" element; it doesn't like to combine with anything else. You breath it in and out your whole life, and yet it does nothing in your lungs.
- You need nitrogen to make the amino acids necessary for you to live. All amino acids have nitrogen in them.
- Plants uptake nitrogen in the form of nitrates (NO3) and ammonium (NH4) found in the soil. Animals then eat the plants (and/or other animals) and get their nitrogen that way.
| nitrogen_compounds_lab_handout.pdf |
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Chemical Bonds homework
| 5._chemical_bonds_homework_2021.docx |
| chemical_bonding_chart.pdf |
Bombardier Beetle assignment
Research the following and submit a 1-1/2 to 2 page research paper: "The Bombardier Beetle uses an explosive discharge as a defensive measure. Explain and illustrate how this works and how this chases off the predator. Be sure to show the chemical reactions involved."
| Bombardier Beetle research papers - student examples |
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AP Chemistry: Density lab
Turn in the 'student worksheet' part only
Turn in the 'student worksheet' part only
| density_lab_instructions.doc |
| density_lab_student_worksheet.doc |