Chem 103 Module 2 Exam Guide 2025
With Questions and Answers Graded A+
why was gold chosen for the Rutherford experiment? - CORRECT ANSWER-it is malleable and strong
enough to create a thin, but strong sheet; if a different, larger atom was used, more a particles would
have been deflected and the small size of the nucleus wouldn't have been portrayed as well
What is the atomic symbol of a neutral element containing 27 electrons and 31 neutrons? - CORRECT
ANSWER-Cobalt
, 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
With Questions and Answers Graded A+
why was gold chosen for the Rutherford experiment? - CORRECT ANSWER-it is malleable and strong
enough to create a thin, but strong sheet; if a different, larger atom was used, more a particles would
have been deflected and the small size of the nucleus wouldn't have been portrayed as well
What is the atomic symbol of a neutral element containing 27 electrons and 31 neutrons? - CORRECT
ANSWER-Cobalt
, 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
