BIO 141 EXAM 1 STUDY GUIDE WITH
COMPLETE SOLUTIONS
atoms and their parts - Correct Answers -the smallest unit that retains the properties of
an element; has a positively charged nucleus with with protons and neutrons, and an
negatively charged electron cloud
ions - Correct Answers -charged atoms/non-neutral atoms; cations are positive and
anions are negative
elements - Correct Answers -A substance that cannot be broken down any further by
chemical means
properties of elements - Correct Answers -all atoms of a particular element have the
same number of protons; the mass of a proton and a neutron is the same and is equal
to 1 dalton; the number of protons is equal to the mass number; atomic numbers are
unique to each element
compounds - Correct Answers -substances made up of two or more elements
relationship between an elements structure and its chemical properties - Correct
Answers -the chemical behavior of an atom is determined by the distribution of
electrons in the atom's electron shells
main elements of life - Correct Answers -carbon, oxygen, hydrogen, and nitrogen
essential elements - Correct Answers -(20-25% of all elements) elements needed by
organisms to live a healthy life and reproduce; humans need 25 and plants need 17
trace elements - Correct Answers -elements that are required by organisms in very
small quantities
orbitals vs. shells - Correct Answers -An orbital is the 3-dimensional space that the
electrons occupy 90% percent of the time; a shells is an energy level that refers to the
distance away from the nucleus and is composed of orbitals
valence - Correct Answers -the number of e- in the outer most shell of an atom or
compound
, types of bonds - Correct Answers -ionic bonds (strong), covalent bonds (strong),
hydrogen bonds (weak), and Van der Walls attraction (weak)
ionic bonds - Correct Answers -when two atoms are joined together through the transfer
of e-; form salts
covalent bonds - Correct Answers -when two atoms are joined together through the
sharing of e-; can be polar or non-polar due to electronegatvitiy
hydrogen bonds - Correct Answers -when a bonded hydrogen atom is attracted to a
neighboring electronegative atoms
Van der Waals interactions - Correct Answers -the sum of the attractive or repulsive
forces between molecules
relationship between molecular shape and function - Correct Answers -a molecule's
shape is determined by the positions of its atoms' valence orbitals. Covalent bonds
result in hybrid orbitals, which are responsible for the shapes of many complex
biological molecules. Shape is the basis for the recognition of one biological molecule
by another. Biological molecules often bind temporarily to each other by forming weak
bonds, but only if their shapes are complementary
models of molecular shape - Correct Answers -the positions of the hybrid orbitals
determine the shapes of the molecules
electronegativity - Correct Answers -the tendency of an atom to draw e- to it (unequal
sharing)
chemical reactions - Correct Answers -breaking and formation of chemical bonds,
leading to the composition of matter
isotopes - Correct Answers -forms of the same element with different numbers of
neutrons
atomic mass - Correct Answers -the sum of the number of protons and neutrons in an
atom
atomic numbr - Correct Answers -the number of protons
mass number - Correct Answers -the total number of particles in the nucleus
hydrogen bonds in water - Correct Answers -due to the partial changes that form from
waters polar covalent bonds, oppositely charged regions of neighboring water
molecules are attracted to each other forming hydrogen bonds
COMPLETE SOLUTIONS
atoms and their parts - Correct Answers -the smallest unit that retains the properties of
an element; has a positively charged nucleus with with protons and neutrons, and an
negatively charged electron cloud
ions - Correct Answers -charged atoms/non-neutral atoms; cations are positive and
anions are negative
elements - Correct Answers -A substance that cannot be broken down any further by
chemical means
properties of elements - Correct Answers -all atoms of a particular element have the
same number of protons; the mass of a proton and a neutron is the same and is equal
to 1 dalton; the number of protons is equal to the mass number; atomic numbers are
unique to each element
compounds - Correct Answers -substances made up of two or more elements
relationship between an elements structure and its chemical properties - Correct
Answers -the chemical behavior of an atom is determined by the distribution of
electrons in the atom's electron shells
main elements of life - Correct Answers -carbon, oxygen, hydrogen, and nitrogen
essential elements - Correct Answers -(20-25% of all elements) elements needed by
organisms to live a healthy life and reproduce; humans need 25 and plants need 17
trace elements - Correct Answers -elements that are required by organisms in very
small quantities
orbitals vs. shells - Correct Answers -An orbital is the 3-dimensional space that the
electrons occupy 90% percent of the time; a shells is an energy level that refers to the
distance away from the nucleus and is composed of orbitals
valence - Correct Answers -the number of e- in the outer most shell of an atom or
compound
, types of bonds - Correct Answers -ionic bonds (strong), covalent bonds (strong),
hydrogen bonds (weak), and Van der Walls attraction (weak)
ionic bonds - Correct Answers -when two atoms are joined together through the transfer
of e-; form salts
covalent bonds - Correct Answers -when two atoms are joined together through the
sharing of e-; can be polar or non-polar due to electronegatvitiy
hydrogen bonds - Correct Answers -when a bonded hydrogen atom is attracted to a
neighboring electronegative atoms
Van der Waals interactions - Correct Answers -the sum of the attractive or repulsive
forces between molecules
relationship between molecular shape and function - Correct Answers -a molecule's
shape is determined by the positions of its atoms' valence orbitals. Covalent bonds
result in hybrid orbitals, which are responsible for the shapes of many complex
biological molecules. Shape is the basis for the recognition of one biological molecule
by another. Biological molecules often bind temporarily to each other by forming weak
bonds, but only if their shapes are complementary
models of molecular shape - Correct Answers -the positions of the hybrid orbitals
determine the shapes of the molecules
electronegativity - Correct Answers -the tendency of an atom to draw e- to it (unequal
sharing)
chemical reactions - Correct Answers -breaking and formation of chemical bonds,
leading to the composition of matter
isotopes - Correct Answers -forms of the same element with different numbers of
neutrons
atomic mass - Correct Answers -the sum of the number of protons and neutrons in an
atom
atomic numbr - Correct Answers -the number of protons
mass number - Correct Answers -the total number of particles in the nucleus
hydrogen bonds in water - Correct Answers -due to the partial changes that form from
waters polar covalent bonds, oppositely charged regions of neighboring water
molecules are attracted to each other forming hydrogen bonds
