MCAT General Chemistry UPDATED
ACTUAL Questions and CORRECT
Answers
protons - CORRECT ANSWER- has a positive charge and mass around 1 amu
neutron - CORRECT ANSWER- has no charge and a mass around 1 amu
electron - CORRECT ANSWER- has a negative charge and negligible mass
atomic number - CORRECT ANSWER- the number of protons in a given element
mass number - CORRECT ANSWER- the sum of an element's protons and neutrons
atomic mass - CORRECT ANSWER- essentially equal to the mass number (the sum of an
element's protons and neutrons)
isotopes - CORRECT ANSWER- atoms of a given element (same atomic number) that have
different mass numbers, they differ in number of neutrons
the 3 isotopes of hydrogen - CORRECT ANSWER- protium, deuterium, tritium
atomic weight - CORRECT ANSWER- the weighted average of the naturally occurring
isotopes of an element
does the periodic table list atomic weights or atomic masses? - CORRECT ANSWER- atomic
weights
Bohr model of the atom - CORRECT ANSWER- a dense, positively charged nucleus is
surrounded by electrons revolving around the nucleus in orbits with distinct energy levels
,Rutherford - CORRECT ANSWER- first postulated that the atom had a dense, positively
charged nucleus that made up only a small fraction of the volume of the atom
quantum - CORRECT ANSWER- - the energy difference between energy levels
- first described by Planck
quantization - CORRECT ANSWER- means that there is not an infinite range of energy
levels available to an electron, electrons can only exist at certain energy levels, the energy of
an electron increases the farther it is from the nucleus
atomic absorption spectrum - CORRECT ANSWER- - unique for each element
- for an electron to jump from a lower energy level to a higher one, it must absorb an amount
of energy precisely equal to the energy difference between the two levels
atomic emission spectrum - CORRECT ANSWER- - unique for each element
- when electrons return from the excited to ground state, they emit an amount of energy equal
to the energy difference between the two levels
quantum mechanical model - CORRECT ANSWER- posits that electrons do not travel in
defined orbits but rather are localized in orbitals
orbital - CORRECT ANSWER- a region of space around the nucleus defined by the
probability of finding an electron in that region of space
Heisenberg uncertainty principle - CORRECT ANSWER- states that is impossible to know
both an electron's positron and its momentum exactly at the same time
how many quantum numbers are there? - CORRECT ANSWER- 4
quantum number - CORRECT ANSWER- completely describe any electron in an atom
principal quantum number - CORRECT ANSWER- - n
- describes the average energy of a shell
,azimuthal quantum number - CORRECT ANSWER- - ℓ
- describes the subshells (s, p, d, f) within a given principal energy level
magnetic quantum number - CORRECT ANSWER- - mℓ
- specifies the particular orbital within a subshell where an electron is likely to be found at a
given moment in time
spin quantum number - CORRECT ANSWER- - ms
- indicates the spin orientation (+/- 1/2) of an electron in an orbital
electron configuration - CORRECT ANSWER- uses spectroscopic notation (combining the n
and ℓ values as a number and letter, respectively) to designate the location of electrons
(n + ℓ) rule - CORRECT ANSWER- electrons fill the principal energy levels and subshells
according to increasing energy
Hund's rule - CORRECT ANSWER- states that subshells with multiple orbitals (p, d, f) fill
electrons so that every orbital in a subshell gets one electron before any of them gets a second
paramagnetic materials - CORRECT ANSWER- have unpaired electrons that align with
magnetic fields, attracting the material to a magnet
diamagnetic materials - CORRECT ANSWER- - have all paired electrons, which cannot
easily be realigned
- repelled by magnets
valence electrons - CORRECT ANSWER- electrons in the outermost shell available for
interaction (bonding) with other atoms
Planck relation (frequency) - CORRECT ANSWER- E = hf
(h is Planck's constant = 6.626e-34 J*s)
, angular momentum of an electron (Bohr model) - CORRECT ANSWER- L = nh/2π
(n is principal quantum number, h is Planck's constant = 6.626e-34 J*s)
energy of an electron (Bohr model) - CORRECT ANSWER- E = -R/n²
(R is Rydberg unit of energy = 2.18e-18 J/electron, n is principal quantum number)
Planck relation (wavelength) - CORRECT ANSWER- E = hc/λ
(h is Planck's constant = 6.626e-34 J*s)
energy of electron transition (Bohr model) - CORRECT ANSWER- E = -R((1/ni²)-(1/nf²))
(R is Rydberg unit of energy = 2.18e-18 J/electron, ni is higher initial value, nf is lower final
value)
maximum number of electrons within a shell - CORRECT ANSWER- 2n²
maximum number of electrons within a subshell - CORRECT ANSWER- 4ℓ + 2
periods in Periodic Table - CORRECT ANSWER- rows, based on the same principal energy
level (n)
groups in Periodic Table - CORRECT ANSWER- columns, elements in the same group have
the same valence shell electron configuration
metals - CORRECT ANSWER- shiny/lustrous, conduct electricity well, malleable and
ductile, found on the left and middle of the Periodic Table
nonmetals - CORRECT ANSWER- dull, poor conductors of electricity, brittle, found on the
right side of Periodic Table
metalloids - CORRECT ANSWER- possess characteristics of both metals and nonmetals,
found in a stair-step pattern starting with boron (B)
ACTUAL Questions and CORRECT
Answers
protons - CORRECT ANSWER- has a positive charge and mass around 1 amu
neutron - CORRECT ANSWER- has no charge and a mass around 1 amu
electron - CORRECT ANSWER- has a negative charge and negligible mass
atomic number - CORRECT ANSWER- the number of protons in a given element
mass number - CORRECT ANSWER- the sum of an element's protons and neutrons
atomic mass - CORRECT ANSWER- essentially equal to the mass number (the sum of an
element's protons and neutrons)
isotopes - CORRECT ANSWER- atoms of a given element (same atomic number) that have
different mass numbers, they differ in number of neutrons
the 3 isotopes of hydrogen - CORRECT ANSWER- protium, deuterium, tritium
atomic weight - CORRECT ANSWER- the weighted average of the naturally occurring
isotopes of an element
does the periodic table list atomic weights or atomic masses? - CORRECT ANSWER- atomic
weights
Bohr model of the atom - CORRECT ANSWER- a dense, positively charged nucleus is
surrounded by electrons revolving around the nucleus in orbits with distinct energy levels
,Rutherford - CORRECT ANSWER- first postulated that the atom had a dense, positively
charged nucleus that made up only a small fraction of the volume of the atom
quantum - CORRECT ANSWER- - the energy difference between energy levels
- first described by Planck
quantization - CORRECT ANSWER- means that there is not an infinite range of energy
levels available to an electron, electrons can only exist at certain energy levels, the energy of
an electron increases the farther it is from the nucleus
atomic absorption spectrum - CORRECT ANSWER- - unique for each element
- for an electron to jump from a lower energy level to a higher one, it must absorb an amount
of energy precisely equal to the energy difference between the two levels
atomic emission spectrum - CORRECT ANSWER- - unique for each element
- when electrons return from the excited to ground state, they emit an amount of energy equal
to the energy difference between the two levels
quantum mechanical model - CORRECT ANSWER- posits that electrons do not travel in
defined orbits but rather are localized in orbitals
orbital - CORRECT ANSWER- a region of space around the nucleus defined by the
probability of finding an electron in that region of space
Heisenberg uncertainty principle - CORRECT ANSWER- states that is impossible to know
both an electron's positron and its momentum exactly at the same time
how many quantum numbers are there? - CORRECT ANSWER- 4
quantum number - CORRECT ANSWER- completely describe any electron in an atom
principal quantum number - CORRECT ANSWER- - n
- describes the average energy of a shell
,azimuthal quantum number - CORRECT ANSWER- - ℓ
- describes the subshells (s, p, d, f) within a given principal energy level
magnetic quantum number - CORRECT ANSWER- - mℓ
- specifies the particular orbital within a subshell where an electron is likely to be found at a
given moment in time
spin quantum number - CORRECT ANSWER- - ms
- indicates the spin orientation (+/- 1/2) of an electron in an orbital
electron configuration - CORRECT ANSWER- uses spectroscopic notation (combining the n
and ℓ values as a number and letter, respectively) to designate the location of electrons
(n + ℓ) rule - CORRECT ANSWER- electrons fill the principal energy levels and subshells
according to increasing energy
Hund's rule - CORRECT ANSWER- states that subshells with multiple orbitals (p, d, f) fill
electrons so that every orbital in a subshell gets one electron before any of them gets a second
paramagnetic materials - CORRECT ANSWER- have unpaired electrons that align with
magnetic fields, attracting the material to a magnet
diamagnetic materials - CORRECT ANSWER- - have all paired electrons, which cannot
easily be realigned
- repelled by magnets
valence electrons - CORRECT ANSWER- electrons in the outermost shell available for
interaction (bonding) with other atoms
Planck relation (frequency) - CORRECT ANSWER- E = hf
(h is Planck's constant = 6.626e-34 J*s)
, angular momentum of an electron (Bohr model) - CORRECT ANSWER- L = nh/2π
(n is principal quantum number, h is Planck's constant = 6.626e-34 J*s)
energy of an electron (Bohr model) - CORRECT ANSWER- E = -R/n²
(R is Rydberg unit of energy = 2.18e-18 J/electron, n is principal quantum number)
Planck relation (wavelength) - CORRECT ANSWER- E = hc/λ
(h is Planck's constant = 6.626e-34 J*s)
energy of electron transition (Bohr model) - CORRECT ANSWER- E = -R((1/ni²)-(1/nf²))
(R is Rydberg unit of energy = 2.18e-18 J/electron, ni is higher initial value, nf is lower final
value)
maximum number of electrons within a shell - CORRECT ANSWER- 2n²
maximum number of electrons within a subshell - CORRECT ANSWER- 4ℓ + 2
periods in Periodic Table - CORRECT ANSWER- rows, based on the same principal energy
level (n)
groups in Periodic Table - CORRECT ANSWER- columns, elements in the same group have
the same valence shell electron configuration
metals - CORRECT ANSWER- shiny/lustrous, conduct electricity well, malleable and
ductile, found on the left and middle of the Periodic Table
nonmetals - CORRECT ANSWER- dull, poor conductors of electricity, brittle, found on the
right side of Periodic Table
metalloids - CORRECT ANSWER- possess characteristics of both metals and nonmetals,
found in a stair-step pattern starting with boron (B)
