CBIO 2200 Lecture Notes - Lecture 2: Alka-Seltzer, Sodium Bicarbonate, Atomic Number

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Notes for CBIO 2200 CRN17428 CH2 Chemistry
(Week 2: 8/16/2016-8/18/2016)
1. Elements, Atoms, Ions and Isotopes: Review of some basic terms and
definitions
a) Element
b) Atom
i. Proton
ii. Neutron
iii. Electron
c) Atomic number (Z)
-Number of protons
-Defines the element
d) Atomic Mass (mass number)
-Can differ based on number of neutrons
-The average atomic mass (calculated from isotopes) is on the periodic
table
e) What happens when there are different numbers of electrons between
atoms of the same element? (Cations-positively charged and Anions-
negatively charged)
f) What happens when there are different numbers of neutrons between
atoms of the same element? (Isotopes)
2. Chemical Bonds
a) The octet rule- atoms of main-group elements tend to combine in such
a way that each atom has eight electrons in its valence shell, giving it
the same electronic configuration as a noble gas.
b) Ionic bonds- transfer of valence electrons between atoms and
generally results in two oppositely charged ions.
The images in these notes are from our textbook. You can download the book for free
at http://cnx.org/content/col11496/latest/.
find more resources at oneclass.com
find more resources at oneclass.com
c) Covalent bonds (sharing electrons between atoms, within a molecule)
d) Polar vs. Non-polar covalent bonds
Non-polar- equal sharing of electrons- no net dipole moment
Water molecules have unequal sharing of electrons (polar-covalent)
bonds. Therefore, it’s partially attracted to other water molecules. Its
an excellent polar solvent.
e) Hydrogen bonds
i. Really, these are a special case of covalent bonds
ii. These are attractions BETWEEN molecules, rather than bonds that
hold atoms together within molecules
iii. BUT they are also important WITHIN large molecules in holding
them in a particular shape
The images in these notes are from our textbook. You can download the book for free
at http://cnx.org/content/col11496/latest/.
find more resources at oneclass.com
find more resources at oneclass.com
3. Chemical reactions
a) Synthesis (anabolism)
Creating something
A + B  AB
ReactantsProducts
b) Decomposition (catabolism)
Taking something apart
AB  A + B
Reactants  Products
c) Exchange
AB + CD  AC + BD
Reactants  Products
d) Reversible
AB  A + B
Forward reaction: left to right
Reverse reaction: right to left
To make reactions happen faster you can: increase temperature, have
more reactants to react with each other, or lower activation energy.
e) Catalysts
i. Often are enzymes in biological systems
-Enzymes decrease the activation energy required for a given
chemical reaction to occur (brings reactants closer together)
-Most often, enzymes are proteins
The images in these notes are from our textbook. You can download the book for free
at http://cnx.org/content/col11496/latest/.
find more resources at oneclass.com
find more resources at oneclass.com