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Chem 103 Module 2 Exam Study Guide
100% Verified.
Atom - 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 - Answer✔A subatomic particle that has a positive charge and that is found in the
nucleus of an atom
neutron - Answer✔A subatomic particle that has no charge and that is found in the nucleus of
an atom
electron - Answer✔A subatomic particle that has a negative charge and is found outside of the
nucleus
masses of subatomic particles - 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 - 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 - 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 - 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 - 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 - Answer✔A charged atom
cation - Answer✔A positively charged ion that loses an electron
anion - Answer✔A negatively charged ion that gains an electron
neutral atoms - Answer✔have the same number of protons and electrons
subatomic particles - Answer✔protons, neutrons, electrons
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nucleus - Answer✔Center of an atom that contains protons and neutrons
Rutherford's discoveries - 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 - Answer✔the electron cloud takes up most of the volume, but
the nucleus takes up most of the mass
atomic mass unit (amu) - Answer✔1/12 the mass of one carbon-12 atom; 1.6605 x 10^-24 g
Dalton (Da) and Unified Atomic Mass Unit (u) - Answer✔alternative unit equivalent to the
atomic mass unit
fundamental unit of charge - Answer✔also known as the elementary charge; the magnitude of
the charge of an electron; e= -1.602 x 10^-19 c (coulomb)
masses of subatomic partibles - Answer✔p = 1.0073 amu
n = 1.0087 amu
e = 0.00055 amu
A person's mass is 100 kg. What is their mass in amu? - Answer✔6.022 x 10^28 amu
how to solve for the number of neutrons in an atom - Answer✔mass number (A) - atomic
number (Z)
how to find the atomic charge of an atom - Answer✔number of protons - number of electrons
chemical symbol - Answer✔a one-, two-, or three-letter abbreviation of the name of an
element
diameter of a nucleus vs diameter of an atom - Answer✔diameter of nucleus is 100,000x
smaller than diameter of atom
What makes atoms unstable - Answer✔when they are isotopes and have a different number of
neutrons than protons
notation of isotopes - Answer✔Lithium-6
(element name) - (mass #)
mass of carbon-12 - Answer✔12 amu
plum pudding model - Answer✔JJ Thomson, 1904; showed that charges in an atom are evenly
distributed; if this was the case, none of the alpha particles would have deflected like they did
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Chem 103 Module 2 Exam Study Guide
100% Verified.
Atom - 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 - Answer✔A subatomic particle that has a positive charge and that is found in the
nucleus of an atom
neutron - Answer✔A subatomic particle that has no charge and that is found in the nucleus of
an atom
electron - Answer✔A subatomic particle that has a negative charge and is found outside of the
nucleus
masses of subatomic particles - 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 - 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 - 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 - 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 - 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 - Answer✔A charged atom
cation - Answer✔A positively charged ion that loses an electron
anion - Answer✔A negatively charged ion that gains an electron
neutral atoms - Answer✔have the same number of protons and electrons
subatomic particles - Answer✔protons, neutrons, electrons
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nucleus - Answer✔Center of an atom that contains protons and neutrons
Rutherford's discoveries - 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 - Answer✔the electron cloud takes up most of the volume, but
the nucleus takes up most of the mass
atomic mass unit (amu) - Answer✔1/12 the mass of one carbon-12 atom; 1.6605 x 10^-24 g
Dalton (Da) and Unified Atomic Mass Unit (u) - Answer✔alternative unit equivalent to the
atomic mass unit
fundamental unit of charge - Answer✔also known as the elementary charge; the magnitude of
the charge of an electron; e= -1.602 x 10^-19 c (coulomb)
masses of subatomic partibles - Answer✔p = 1.0073 amu
n = 1.0087 amu
e = 0.00055 amu
A person's mass is 100 kg. What is their mass in amu? - Answer✔6.022 x 10^28 amu
how to solve for the number of neutrons in an atom - Answer✔mass number (A) - atomic
number (Z)
how to find the atomic charge of an atom - Answer✔number of protons - number of electrons
chemical symbol - Answer✔a one-, two-, or three-letter abbreviation of the name of an
element
diameter of a nucleus vs diameter of an atom - Answer✔diameter of nucleus is 100,000x
smaller than diameter of atom
What makes atoms unstable - Answer✔when they are isotopes and have a different number of
neutrons than protons
notation of isotopes - Answer✔Lithium-6
(element name) - (mass #)
mass of carbon-12 - Answer✔12 amu
plum pudding model - Answer✔JJ Thomson, 1904; showed that charges in an atom are evenly
distributed; if this was the case, none of the alpha particles would have deflected like they did
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