ACS CHEMISTRY GENERAL EXAM 2025
ACTUAL EXAM COMPLETE QUESTIONS WITH
DETAILED VERIFIED ANSWERS / ALREADY
GRADED A+
1. how to find the correct number of neutrons
• (answer) mass number - atomic number
2. Forms of the same elements that differ in amount of neutrons
• (answer) isotopes
3. What particle, if lost from the nucleus, would NOT cause a change in the atomic
number?
• (answer) a neutron because it has no charge
4. 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?
• (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).
5. An atom has a valence shell configuration of 1s1. To which group of elements
on the periodic table does it belong?
• (answer) IA (alkali metals)
6. electromagnetic spectrum
• (answer) the range of all electromagnetic radiation, arranged by
wavelength or frequency
7. The greater the wavelength of a photon..?
• (answer) the lower its frequency
,8. The greater the frequency of a photon...?
• (answer) the shorter its wavelength
9. Light energy formula
• (answer) E = hν
10. What does C in the light energy formula represent?
• (answer) the speed of light (2.998 × 10⁸ m/s) – appears in c = λν, not
directly in E = hν
11. Give the ground-state electron configuration of an atom in the second period
• (answer) 1s² 2s¹ (lithium)
12. Electrons configuration rule that states electrons do not pair until they have
to. (put one electrons in each electron domain then pair up)
• (answer) Hund's rule
13. An experimental phenomena associated with atoms having unpaired
electrons - which states such substances are attracted to magnetic fields
• (answer) paramagnetism
14. Which drop in energy level results in the greatest emission of energy?
• (answer) n=2 to n=1
15. quantum numbers
• (answer) set of four numbers (n, l, m_l, m_s) that describe the energy
state and location of an electron in an atom
16. What do the 4 quantum numbers stand for?
• (answer) n = energy level (principal); l = azimuthal (0 to n-1); m_l =
magnetic (−l to +l); m_s = spin (+½ or −½)
17. List the quantum numbers for the s, p, d, and f orbitals
• (answer) s: n=1, l=0, m_l=0; p: n=2, l=1, m_l = -1,0,+1; d: n=3, l=2, m_l = -2,-
1,0,+1,+2; f: n=4, l=3, m_l = -3,-2,-1,0,+1,+2,+3
, 18. Py orbital
• (answer) a p orbital oriented along the y-axis, with two lobes and a nodal
plane along the xz-plane
19. Which element is represented by X
• (answer) Chromium
20. What two subatomic particles have the most mass, but occupy very little of
the volume of an atom
• (answer) protons and neutrons
21. Define Isolecronic
• (answer) having the same number of electrons (correct spelling:
isoelectronic)
22. How does a sodium ion differ from a sodium atom?
• (answer) the sodium ion has fewer electrons
23. two or more compounds with the same formula but a different arrangement
of atoms in the molecule and different properties
• (answer) isomers
24. two or more different physical forms in which an element can exist. Graphite,
charcoal, and diamond are all ______ of carbon.
• (answer) allotropes
25. What makes up an alpha particle?
• (answer) 2 protons and 2 neutrons
26. What did Millikan discover from his oil drop experiments?
• (answer) the magnitude of the charge on an electron
27. Periods vs Groups
• (answer) periods are horizontal rows (same principal quantum number);
groups are vertical columns (same valence electron configuration)
ACTUAL EXAM COMPLETE QUESTIONS WITH
DETAILED VERIFIED ANSWERS / ALREADY
GRADED A+
1. how to find the correct number of neutrons
• (answer) mass number - atomic number
2. Forms of the same elements that differ in amount of neutrons
• (answer) isotopes
3. What particle, if lost from the nucleus, would NOT cause a change in the atomic
number?
• (answer) a neutron because it has no charge
4. 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?
• (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).
5. An atom has a valence shell configuration of 1s1. To which group of elements
on the periodic table does it belong?
• (answer) IA (alkali metals)
6. electromagnetic spectrum
• (answer) the range of all electromagnetic radiation, arranged by
wavelength or frequency
7. The greater the wavelength of a photon..?
• (answer) the lower its frequency
,8. The greater the frequency of a photon...?
• (answer) the shorter its wavelength
9. Light energy formula
• (answer) E = hν
10. What does C in the light energy formula represent?
• (answer) the speed of light (2.998 × 10⁸ m/s) – appears in c = λν, not
directly in E = hν
11. Give the ground-state electron configuration of an atom in the second period
• (answer) 1s² 2s¹ (lithium)
12. Electrons configuration rule that states electrons do not pair until they have
to. (put one electrons in each electron domain then pair up)
• (answer) Hund's rule
13. An experimental phenomena associated with atoms having unpaired
electrons - which states such substances are attracted to magnetic fields
• (answer) paramagnetism
14. Which drop in energy level results in the greatest emission of energy?
• (answer) n=2 to n=1
15. quantum numbers
• (answer) set of four numbers (n, l, m_l, m_s) that describe the energy
state and location of an electron in an atom
16. What do the 4 quantum numbers stand for?
• (answer) n = energy level (principal); l = azimuthal (0 to n-1); m_l =
magnetic (−l to +l); m_s = spin (+½ or −½)
17. List the quantum numbers for the s, p, d, and f orbitals
• (answer) s: n=1, l=0, m_l=0; p: n=2, l=1, m_l = -1,0,+1; d: n=3, l=2, m_l = -2,-
1,0,+1,+2; f: n=4, l=3, m_l = -3,-2,-1,0,+1,+2,+3
, 18. Py orbital
• (answer) a p orbital oriented along the y-axis, with two lobes and a nodal
plane along the xz-plane
19. Which element is represented by X
• (answer) Chromium
20. What two subatomic particles have the most mass, but occupy very little of
the volume of an atom
• (answer) protons and neutrons
21. Define Isolecronic
• (answer) having the same number of electrons (correct spelling:
isoelectronic)
22. How does a sodium ion differ from a sodium atom?
• (answer) the sodium ion has fewer electrons
23. two or more compounds with the same formula but a different arrangement
of atoms in the molecule and different properties
• (answer) isomers
24. two or more different physical forms in which an element can exist. Graphite,
charcoal, and diamond are all ______ of carbon.
• (answer) allotropes
25. What makes up an alpha particle?
• (answer) 2 protons and 2 neutrons
26. What did Millikan discover from his oil drop experiments?
• (answer) the magnitude of the charge on an electron
27. Periods vs Groups
• (answer) periods are horizontal rows (same principal quantum number);
groups are vertical columns (same valence electron configuration)
