ACS Chemistry general Exam questions and answers
Graded A+| 2026 Updated
Layout of an element (mass # & atomic #) - ✅✅
atomic number = - ✅✅# of protons
mass number = - ✅✅# of protons + neutrons
the number of protons in a neutral atom will equal the - ✅✅# of electrons
how to find the correct number of neutrons - ✅✅mass number - atomic
number
Forms of the same elements that differ in amount of neutrons - ✅✅isotopes
What particle, if lost from the nucleus, would NOT cause a change in the atomic
number? - ✅✅a neutron because it has no charge
When alpha particles were shot at a metal foil target, most passed through
without deflections, while others deflected at large angles. What did this suggest
to Rutherford? - ✅✅that the atoms of the metal were mostly empty space,
while the nucleus consisted of most of the mass which included highly condensed
positive particles (which caused the deflection).
,An atom has a valence shell configuration of 1s1. To which group of elements on
the periodic table does it belong? - ✅✅IA
alkali metals
electromagnetic spectrum - ✅✅
The greater the wavelength of a photon..? - ✅✅the lower its frequency
The greater the frequency of a photon...? - ✅✅the shorter its wavelength
Light energy formula - ✅✅
What does C in the light energy formula represent? - ✅✅
Give the ground-state electron configuration of an atom in the second period -
✅✅1s2 2s1
Electrons configuration rule that states electrons do not pair until they have to.
(put one electrons in each electron domain then pair up) - ✅✅Hund's rule
An experimental phenomena associated with atoms having unpaired electrons -
which states such substances are attracted to magnetic fields -
✅✅Paramagnetism
, Which drop in energy level results in the greatest emission of energy? - ✅✅n=2
to n=1
quantum numbers - ✅✅
What do the 4 quantum numbers stand for? - ✅✅n = energy level
l = (n-1)
ml -l to l
mn 1/2 or -1/2 (spin)
List the quantum numbers for the s, p, d, and f orbitals - ✅✅s 1,0,0
p 2, 1, -1-0-1
d 3, 2, -2--1-0-1-2
f 4, 3 -3--2--1-0-1-2-3
Py orbital - ✅✅
Which element is represented by X - ✅✅Chromium
What two subatomic particles have the most mass, but occupy very little of the
volume of an atom - ✅✅protons and neutrons
Define Isoelectronic - ✅✅Having the same amount of electrons
Graded A+| 2026 Updated
Layout of an element (mass # & atomic #) - ✅✅
atomic number = - ✅✅# of protons
mass number = - ✅✅# of protons + neutrons
the number of protons in a neutral atom will equal the - ✅✅# of electrons
how to find the correct number of neutrons - ✅✅mass number - atomic
number
Forms of the same elements that differ in amount of neutrons - ✅✅isotopes
What particle, if lost from the nucleus, would NOT cause a change in the atomic
number? - ✅✅a neutron because it has no charge
When alpha particles were shot at a metal foil target, most passed through
without deflections, while others deflected at large angles. What did this suggest
to Rutherford? - ✅✅that the atoms of the metal were mostly empty space,
while the nucleus consisted of most of the mass which included highly condensed
positive particles (which caused the deflection).
,An atom has a valence shell configuration of 1s1. To which group of elements on
the periodic table does it belong? - ✅✅IA
alkali metals
electromagnetic spectrum - ✅✅
The greater the wavelength of a photon..? - ✅✅the lower its frequency
The greater the frequency of a photon...? - ✅✅the shorter its wavelength
Light energy formula - ✅✅
What does C in the light energy formula represent? - ✅✅
Give the ground-state electron configuration of an atom in the second period -
✅✅1s2 2s1
Electrons configuration rule that states electrons do not pair until they have to.
(put one electrons in each electron domain then pair up) - ✅✅Hund's rule
An experimental phenomena associated with atoms having unpaired electrons -
which states such substances are attracted to magnetic fields -
✅✅Paramagnetism
, Which drop in energy level results in the greatest emission of energy? - ✅✅n=2
to n=1
quantum numbers - ✅✅
What do the 4 quantum numbers stand for? - ✅✅n = energy level
l = (n-1)
ml -l to l
mn 1/2 or -1/2 (spin)
List the quantum numbers for the s, p, d, and f orbitals - ✅✅s 1,0,0
p 2, 1, -1-0-1
d 3, 2, -2--1-0-1-2
f 4, 3 -3--2--1-0-1-2-3
Py orbital - ✅✅
Which element is represented by X - ✅✅Chromium
What two subatomic particles have the most mass, but occupy very little of the
volume of an atom - ✅✅protons and neutrons
Define Isoelectronic - ✅✅Having the same amount of electrons
