50 questions 2 pts per questions
Curve:
1.5 or 1.25 off per wrong answer
96% with 2 wrong A
97% curved
A
30% (15 out of 50) F
47.5%
F
Chapter 1
Life, hierarchy of complexity
Atom
Molecules
Cells (simplest level of living complexity)
Tissues
Organs
Systems
Multicellular organisms
Populations
Community
Ecosystem
Biosphere
What is science? What is natural science?
Question/problem
Hypothesis
Theory
Cell Theory
Germ Theory
Chapter 2
Atoms
Protons +
Neutrons 0
Electrons –
Atomic number: # or protons; identifies the
element that the atom is
Hydrogen 1 proton; 0 neutrons; 1 electron
Deuterium 1 proton; 1 neutron; 1 electron (isotope
of hydrogen)
Helium 2 protons; 2 neutron; 2 electrons
(different chemical properties than H)
1) Covalent bond: shares electrons, occur if more
stability results
2) Ionic bond: transfer of electrons, bond is based
on electrical attraction
3) Hydrogen bond: attraction between polar
molecules
Polar molecules have an uneven distribution of
electrons, have a + pole and a – pole
Water is polar:
It has surface tension (it sticks to itself, forms
droplets, cohesive)
It dissolves ionic compounds (salts), other polar
molecules. Does not dissolve non-polar (e.g. oil)
Water buffers temperature changes. Lot of heat
needed to warm water, water must lose much heat
to cool. Water absorbs much heat when it
evaporates. Water is a good heat sink.
Molecule: more than one atom bonded together
Compound: more than one element bonded
together
Water has pH
H20  H+ + OHWater disassociates
Pure water [H+] and [OH-] are equal
pH = 7 in pure water
if more H+ than OH-, pH < 7, acidic
if less H+ than OH-, pH > 7, basic
pH 2 pOH 2 pH 7 pOH 7
HCl acid
NaOH base
Buffered solution resists changes in pH (either
direction)