Objectives for Introduction to biology and the chemistry of life (chapter 2 and 3) :
Know the steps of the scientific method
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Observations- google someone else’s observation but make sure it is a valid source
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Empirical observation- you are doing the actual observing
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Questions- ask them
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Hypothesize- nothing more than an answer to a question (guess is an answer)
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Test hypothesis- looking up the answer given
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Conclusion- you have the information and this will effect what you do with it
What is a hypothesis? -
an educated guess based on information learned
Who is Rutherford, what did he do, why do we care? -
Scientist; he did the gold foil experiment (shot alpha particles at
foil and expected most of them to bounce back) 98% went through the foil; this shows that mass of an atom is clustered
in the center and the rest is air.
What are the atoms of life? –
carbon, oxygen, nitrogen, hydrogen
Define the following completely, learn the use and meaning of each word and the phenomena it represents:
Atom-
smallest unit of matter; made up of 3 subatomic particles; atoms never die; each specific type of
atom is a chemical element
Proton-
positive and found in the nucleus; same number as electrons; has mass
Electron-
negative and found in orbitals; same number as protons; no mass
Neutron-
neutral and found in the nucleus; number can vary; has mass
Ion-
if electrons are gained or lost from an atom
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Cation- positive; has lost electrons
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Anion- negative; has gained electrons
Isotope-
multiple forms of an element that differ in number of neutrons; different mass same element;
atomic masses are the averages of the weights of different isotopes in an element
Isomer-
Two structures with an identical molecular formula but different structures and characteristics
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Structural isomers- contain the same atoms but in different bonding relationships
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Stereoisomers- identical bonding relationships, but the spatial positioning of the atoms differs in
the two isomers
Geometric isomers- positioning around double bond
Enantiomers- mirror image of another molecule
Orbital-
s orbitals are spherical and p orbitals are propeller or dumbbell shaped; electrons fill these and
the shape will determine the function; each orbital can hold only 2 electrons; atoms with more than 2
have more than one orbital
Energy shell
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1
st
shell- 1 spherical (s) orbital that holds 2 electrons
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2
nd
shell- 1s orbital (2s) and 3 dumbbell shaped orbitals (2p) that can hold 4 pairs of electrons
Atom’s nucleus-
where protons and neutrons are held
Valence electrons-
electrons in the outermost energy shell
Octet rule-
atoms are stable when their outer shell is full; normally 8 electrons; hydrogen is stable at 2
Atomic number-
number of protons
Atomic mass-
average mass of all the isotopes of that element
Describe, explain and learn about the following chemical bonds and interactions:
Covalent Polar-
When two atoms with different electronegativity’s form a covalent bond, the shared electrons
