ACS Chemistry General Exam Questions with
Correct Answers Latest 2025/2026
What particle, if lost from the nucleus, would NOT cause a change in the atomic number? - CORRECT
ANSWER: - 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? - CORRECT ANSWER: - 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? - CORRECT ANSWER: – IA alkali metals
The greater the wavelength of a photon..? - CORRECT ANSWER: - the lower its frequency
The greater the frequency of a photon...? - CORRECT ANSWER: - the shorter its wavelength
Give the ground-state electron configuration of an atom in the second period - CORRECT ANSWER: - 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) - CORRECT ANSWER: - Hund's rule
An experimental phenomena associated with atoms having unpaired electrons - which states such
substances are attracted to magnetic fields - CORRECT ANSWER: - Para magnetism
Which drop in energy level results in the greatest emission of energy? - CORRECT ANSWER: - n=2 to n=1
pg. 1
,What do the 4 quantum numbers stand for? - CORRECT ANSWER: - 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 - CORRECT ANSWER: - 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
Which element is represented by X - CORRECT ANSWER: - Chromium
What two subatomic particles have the most mass, but occupy very little of the volume of an atom -
CORRECT ANSWER: - protons and neutrons
Define Isoelectronic - CORRECT ANSWER: - Having the same amount of electrons
How does a sodium ion differ from a sodium atom? - CORRECT ANSWER: - the sodium ion has fewer
electrons
two or more compounds with the same formula but a different arrangement of atoms in the molecule
and different properties - CORRECT ANSWER: - isomer
two or more different physical forms in which an element can exist. Graphite, charcoal, and diamond are
all of carbon. - CORRECT ANSWER: - allotropes
What makes up an alpha particle? - CORRECT ANSWER: - 2 protons and 2 neutrons
What did Millikan discover from his oil drop experiments? - CORRECT ANSWER: - the magnitude of the
charge on an electron
pg. 2
, when an atom of an electropositive atom becomes an ion it..? - CORRECT ANSWER: - becomes larger
Nearly all the mass in an atom is located because both & are located there,
and each of these particles have a mass larger than the - CORRECT ANSWER: - inside the
nucleus
protons & neutrons
electron
Classify the following as an element, compound, or mixture. If it is a mixture, decide if it is a
homogeneous or heterogeneous mixture.
1 Sugar
2 Spaghetti Sauce
3 Phosphorus - CORRECT ANSWER: - 1 compound, not a mixture
2 mixture, heterogenous
3 element
Properties that do depend on the amount of matter present. - CORRECT ANSWER: - extensive
List the shape, electron domain geometry, and predicted bond angle of a molecule with 6 electron
domains - CORRECT ANSWER: - Octahedral
90º
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (4
bonding 0 nonbonding) - CORRECT ANSWER: - electron domain geometry: tetrahedral
molecular geometry: tetrahedral
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (3
bonding 1 nonbonding) - CORRECT ANSWER: - electron domain geometry: tetrahedral
molecular geometry: trigonal pyramidal
ex: NH3
pg. 3
Correct Answers Latest 2025/2026
What particle, if lost from the nucleus, would NOT cause a change in the atomic number? - CORRECT
ANSWER: - 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? - CORRECT ANSWER: - 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? - CORRECT ANSWER: – IA alkali metals
The greater the wavelength of a photon..? - CORRECT ANSWER: - the lower its frequency
The greater the frequency of a photon...? - CORRECT ANSWER: - the shorter its wavelength
Give the ground-state electron configuration of an atom in the second period - CORRECT ANSWER: - 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) - CORRECT ANSWER: - Hund's rule
An experimental phenomena associated with atoms having unpaired electrons - which states such
substances are attracted to magnetic fields - CORRECT ANSWER: - Para magnetism
Which drop in energy level results in the greatest emission of energy? - CORRECT ANSWER: - n=2 to n=1
pg. 1
,What do the 4 quantum numbers stand for? - CORRECT ANSWER: - 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 - CORRECT ANSWER: - 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
Which element is represented by X - CORRECT ANSWER: - Chromium
What two subatomic particles have the most mass, but occupy very little of the volume of an atom -
CORRECT ANSWER: - protons and neutrons
Define Isoelectronic - CORRECT ANSWER: - Having the same amount of electrons
How does a sodium ion differ from a sodium atom? - CORRECT ANSWER: - the sodium ion has fewer
electrons
two or more compounds with the same formula but a different arrangement of atoms in the molecule
and different properties - CORRECT ANSWER: - isomer
two or more different physical forms in which an element can exist. Graphite, charcoal, and diamond are
all of carbon. - CORRECT ANSWER: - allotropes
What makes up an alpha particle? - CORRECT ANSWER: - 2 protons and 2 neutrons
What did Millikan discover from his oil drop experiments? - CORRECT ANSWER: - the magnitude of the
charge on an electron
pg. 2
, when an atom of an electropositive atom becomes an ion it..? - CORRECT ANSWER: - becomes larger
Nearly all the mass in an atom is located because both & are located there,
and each of these particles have a mass larger than the - CORRECT ANSWER: - inside the
nucleus
protons & neutrons
electron
Classify the following as an element, compound, or mixture. If it is a mixture, decide if it is a
homogeneous or heterogeneous mixture.
1 Sugar
2 Spaghetti Sauce
3 Phosphorus - CORRECT ANSWER: - 1 compound, not a mixture
2 mixture, heterogenous
3 element
Properties that do depend on the amount of matter present. - CORRECT ANSWER: - extensive
List the shape, electron domain geometry, and predicted bond angle of a molecule with 6 electron
domains - CORRECT ANSWER: - Octahedral
90º
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (4
bonding 0 nonbonding) - CORRECT ANSWER: - electron domain geometry: tetrahedral
molecular geometry: tetrahedral
List the electron domain geometry & molecular geometry of a molecule with 4 electron domains (3
bonding 1 nonbonding) - CORRECT ANSWER: - electron domain geometry: tetrahedral
molecular geometry: trigonal pyramidal
ex: NH3
pg. 3
