UMN BIOL 1009 EXAM 1 (Dean/Scott) QUESTIONS
AND CORRECT ANSWERS
matter - ANSWER anything that takes up space and has mass, made up of elements
element - ANSWER cannot be broken into a simpler substance
92 naturally occurring
compound - ANSWER substance consisting of two or more different elements in a fixed ratio
eg: NaCl sodium chloride
properties of compounds - ANSWER properties of compounds are different than those of the
elements which make it up
oxygen, carbon, hydrogren, nitrogen - ANSWER essential elements that make up 96% of
human body
trace elements - ANSWER required by living organisms in small quantities
atom - ANSWER smallest unit of matter that still retains its properties
protons, neutrons, electrons - ANSWER examples of subatomic particles
,protons (pos) neutrons (neutral) electrons (negative)
atomic nucleus - ANSWER protons and neutrons at the center of the atom.
atomic number - ANSWER number of protons in an atom which is unique to the element.
mass number, atomic mass - ANSWER sum of number of protons and neutrons, mass number
approximates the atomic mass.
isotopes - ANSWER atoms with differing numbers of neutrons. an element usually a
combination of different isotopes
radioactive isotope - ANSWER unstable isotope where the nucleus decays spontaneously
giving off particles and energy
energy - ANSWER capacity to cause change
potential energy - ANSWER energy possessed because of structure or location,
electrons have potential energy given their arrangement around the nucleus
potential energy of electron - ANSWER -electrons energy correlated with its average distance
from the nucleus
,- changes in every levels only occur in fixed incriments
- when electrons absorb energy they move to a more distant shell and falls in when loses
energy
chemical behavior of an atom - ANSWER depends largely on the number of electrons in the
outermost shell>>>> valence shell
valence electrons - ANSWER electrons in the outer shell aka valence shell
orbital - ANSWER 3D space where an electron can be found 90% of the time ( an electrons
exact location cannot be known)
covalent bond - ANSWER sharing of a pair of valence electrons by two atoms, occurs when
atoms are close enough for orbitals to overlap
molecule - ANSWER 2 or more atoms joined by a covalent bond
double bond - ANSWER sharing of two pairs of electrons between two atoms
valence - ANSWER often thought of as bonding capacity, the number of unpaired electrons
needed to complete the outer shell.
, electronegativity - ANSWER attraction of a particular atom for the electrons of of a covalent
bond.
- the greater the electronegativity the more strongly it pulls the shared pair of electrons
towards itself.
nonpolar covalent bond - ANSWER the electron pair is shared equally in a covalent bond
because the elements have equal E-negativity
polar covalent bond - ANSWER unequal sharing of the electron pair if one of the atoms is
more E-neg than the other.
E-negativity of Oxygen - ANSWER oxygen has a high E-neg meaning it creates a partial
charge by pulling the electrons closer to it.
ion - ANSWER charged ion or particle. it has either gained or lost an electron.
cation - ANSWER positively charged ion
anion - ANSWER negatively charged ion
ionic bond - ANSWER attraction between a cation and an anion.
AND CORRECT ANSWERS
matter - ANSWER anything that takes up space and has mass, made up of elements
element - ANSWER cannot be broken into a simpler substance
92 naturally occurring
compound - ANSWER substance consisting of two or more different elements in a fixed ratio
eg: NaCl sodium chloride
properties of compounds - ANSWER properties of compounds are different than those of the
elements which make it up
oxygen, carbon, hydrogren, nitrogen - ANSWER essential elements that make up 96% of
human body
trace elements - ANSWER required by living organisms in small quantities
atom - ANSWER smallest unit of matter that still retains its properties
protons, neutrons, electrons - ANSWER examples of subatomic particles
,protons (pos) neutrons (neutral) electrons (negative)
atomic nucleus - ANSWER protons and neutrons at the center of the atom.
atomic number - ANSWER number of protons in an atom which is unique to the element.
mass number, atomic mass - ANSWER sum of number of protons and neutrons, mass number
approximates the atomic mass.
isotopes - ANSWER atoms with differing numbers of neutrons. an element usually a
combination of different isotopes
radioactive isotope - ANSWER unstable isotope where the nucleus decays spontaneously
giving off particles and energy
energy - ANSWER capacity to cause change
potential energy - ANSWER energy possessed because of structure or location,
electrons have potential energy given their arrangement around the nucleus
potential energy of electron - ANSWER -electrons energy correlated with its average distance
from the nucleus
,- changes in every levels only occur in fixed incriments
- when electrons absorb energy they move to a more distant shell and falls in when loses
energy
chemical behavior of an atom - ANSWER depends largely on the number of electrons in the
outermost shell>>>> valence shell
valence electrons - ANSWER electrons in the outer shell aka valence shell
orbital - ANSWER 3D space where an electron can be found 90% of the time ( an electrons
exact location cannot be known)
covalent bond - ANSWER sharing of a pair of valence electrons by two atoms, occurs when
atoms are close enough for orbitals to overlap
molecule - ANSWER 2 or more atoms joined by a covalent bond
double bond - ANSWER sharing of two pairs of electrons between two atoms
valence - ANSWER often thought of as bonding capacity, the number of unpaired electrons
needed to complete the outer shell.
, electronegativity - ANSWER attraction of a particular atom for the electrons of of a covalent
bond.
- the greater the electronegativity the more strongly it pulls the shared pair of electrons
towards itself.
nonpolar covalent bond - ANSWER the electron pair is shared equally in a covalent bond
because the elements have equal E-negativity
polar covalent bond - ANSWER unequal sharing of the electron pair if one of the atoms is
more E-neg than the other.
E-negativity of Oxygen - ANSWER oxygen has a high E-neg meaning it creates a partial
charge by pulling the electrons closer to it.
ion - ANSWER charged ion or particle. it has either gained or lost an electron.
cation - ANSWER positively charged ion
anion - ANSWER negatively charged ion
ionic bond - ANSWER attraction between a cation and an anion.
