Chem 103 Module 2 UPDATED Exam
Questions and CORRECT Answers
atom - CORRECT ANSWER -Basic unit of matter; made of protons, neutrons, and
electrons; have a nucleus that contains p and n and an electron cloud that surrounds it
proton - CORRECT ANSWER -A subatomic particle that has a positive charge and that is
found in the nucleus of an atom
neutron - CORRECT ANSWER -A subatomic particle that has no charge and that is found
in the nucleus of an atom
electron - CORRECT ANSWER -A subatomic particle that has a negative charge and is
found outside of the nucleus
masses of subatomic particles - CORRECT ANSWER -the proton and neutron have
almost the same mass, and the electron is 2000 x lighter; protons and neutrons are each about 1
amu
electron cloud - CORRECT ANSWER -a region around the nucleus of an atom where
electrons are likely to be found; used because it is hard to tell exactly where electrons are at a
given moment
atomic number - CORRECT ANSWER -the number of protons in the nucleus of an atom;
represented by the letter Z; written in the subscript in from of the atomic symbol; all atoms of the
same element have this same value; this number does not change, therefore it determines the type
of atom
mass number - CORRECT ANSWER -the total number of protons and neutrons in the
nucleus of an atom; represented by the letter A; written in the superscript in from of a chemical
symbol; this number can differ due to isotopes (when the # of neutrons is different)
, isotopes - CORRECT ANSWER -Atoms of the same element that have different numbers
of neutrons; all atoms have them; all isotopes of an element have similar chemical properties
ion - CORRECT ANSWER -A charged atom
cation - CORRECT ANSWER -A positively charged ion that loses an electron
anion - CORRECT ANSWER -A negatively charged ion that gains an electron
neutral atoms - CORRECT ANSWER -have the same number of protons and electrons
subatomic particles - CORRECT ANSWER -protons, neutrons, electrons
nucleus - CORRECT ANSWER -Center of an atom that contains protons and neutrons
Rutherford's discoveries - CORRECT ANSWER -discovered that protons are much larger
than electrons and they are concentrated in the center of the atom, or the nucleus; did the atom
scattering experiment with the alpha particles and the gold foil to demonstrate that the positive
charges of an atom are concentrated in the center and not evenly distributed (which the plum
pudding model described); a small # of alpha particles were significantly deflected (they hit right
on the small nucleus)
volume and mass of an atom - CORRECT ANSWER -the electron cloud takes up most of
the volume, but the nucleus takes up most of the mass
atomic mass unit (amu) - CORRECT ANSWER -1/12 the mass of one carbon-12 atom;
1.6605 x 10^-24 g
Dalton (Da) and Unified Atomic Mass Unit (u) - CORRECT ANSWER -alternative unit
equivalent to the atomic mass unit
Questions and CORRECT Answers
atom - CORRECT ANSWER -Basic unit of matter; made of protons, neutrons, and
electrons; have a nucleus that contains p and n and an electron cloud that surrounds it
proton - CORRECT ANSWER -A subatomic particle that has a positive charge and that is
found in the nucleus of an atom
neutron - CORRECT ANSWER -A subatomic particle that has no charge and that is found
in the nucleus of an atom
electron - CORRECT ANSWER -A subatomic particle that has a negative charge and is
found outside of the nucleus
masses of subatomic particles - CORRECT ANSWER -the proton and neutron have
almost the same mass, and the electron is 2000 x lighter; protons and neutrons are each about 1
amu
electron cloud - CORRECT ANSWER -a region around the nucleus of an atom where
electrons are likely to be found; used because it is hard to tell exactly where electrons are at a
given moment
atomic number - CORRECT ANSWER -the number of protons in the nucleus of an atom;
represented by the letter Z; written in the subscript in from of the atomic symbol; all atoms of the
same element have this same value; this number does not change, therefore it determines the type
of atom
mass number - CORRECT ANSWER -the total number of protons and neutrons in the
nucleus of an atom; represented by the letter A; written in the superscript in from of a chemical
symbol; this number can differ due to isotopes (when the # of neutrons is different)
, isotopes - CORRECT ANSWER -Atoms of the same element that have different numbers
of neutrons; all atoms have them; all isotopes of an element have similar chemical properties
ion - CORRECT ANSWER -A charged atom
cation - CORRECT ANSWER -A positively charged ion that loses an electron
anion - CORRECT ANSWER -A negatively charged ion that gains an electron
neutral atoms - CORRECT ANSWER -have the same number of protons and electrons
subatomic particles - CORRECT ANSWER -protons, neutrons, electrons
nucleus - CORRECT ANSWER -Center of an atom that contains protons and neutrons
Rutherford's discoveries - CORRECT ANSWER -discovered that protons are much larger
than electrons and they are concentrated in the center of the atom, or the nucleus; did the atom
scattering experiment with the alpha particles and the gold foil to demonstrate that the positive
charges of an atom are concentrated in the center and not evenly distributed (which the plum
pudding model described); a small # of alpha particles were significantly deflected (they hit right
on the small nucleus)
volume and mass of an atom - CORRECT ANSWER -the electron cloud takes up most of
the volume, but the nucleus takes up most of the mass
atomic mass unit (amu) - CORRECT ANSWER -1/12 the mass of one carbon-12 atom;
1.6605 x 10^-24 g
Dalton (Da) and Unified Atomic Mass Unit (u) - CORRECT ANSWER -alternative unit
equivalent to the atomic mass unit
