ACS CHEMISTRY 131 FINAL EXAM QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE
2026/2027
Atomic Structures - Answers Know all the problems except #7,14,15
When looking at the atomic structure what does the left-hand subscript represent - Answers
Left hand subscript = atomic number
When looking at the atomic structure what does the left-hand superscript represent - Answers
The mass number
Where on the atomic structure would we find the ionic change (if the isotope has one) - Answers
On the right hand super-script
The mass number = a combination of what two things - Answers Mass number is the sum of all
the number of protons and neutrons
The atomic number equals what? - Answers The atomic number = the number of protons
- Found on left side subscript
If there is no charge on the isotope what can we assume about its # of electrons - Answers We
can assume that its number of electrons is equal to its number of protons
What is the definition of an isotope - Answers Isotopes are forms of the same element that
differ only in their number of neutrons in the nuclei
- Atomic models will be the same with same subscripts on the left but different superscripts on
the left
Give an example of an isotope - Answers ²³⁵U and ²³⁸U
What particle can you remove from a nucleus and have no change to an elements atomic
number - Answers The neutrons because they carry no charge
What type of charge is associated with the following: proton, alpha particle, beta particle,
neutron - Answers Proton: one positive charge
Alpha particle: two positive charges
Beta particle: one negative charge
Neutron: neutral, no charge
What was concluded from Ernest Rutherford's experiment - Answers That alpha particles when
shot at a metal target mostly passed through but some were deflected at large angles.
2026/2027
Atomic Structures - Answers Know all the problems except #7,14,15
When looking at the atomic structure what does the left-hand subscript represent - Answers
Left hand subscript = atomic number
When looking at the atomic structure what does the left-hand superscript represent - Answers
The mass number
Where on the atomic structure would we find the ionic change (if the isotope has one) - Answers
On the right hand super-script
The mass number = a combination of what two things - Answers Mass number is the sum of all
the number of protons and neutrons
The atomic number equals what? - Answers The atomic number = the number of protons
- Found on left side subscript
If there is no charge on the isotope what can we assume about its # of electrons - Answers We
can assume that its number of electrons is equal to its number of protons
What is the definition of an isotope - Answers Isotopes are forms of the same element that
differ only in their number of neutrons in the nuclei
- Atomic models will be the same with same subscripts on the left but different superscripts on
the left
Give an example of an isotope - Answers ²³⁵U and ²³⁸U
What particle can you remove from a nucleus and have no change to an elements atomic
number - Answers The neutrons because they carry no charge
What type of charge is associated with the following: proton, alpha particle, beta particle,
neutron - Answers Proton: one positive charge
Alpha particle: two positive charges
Beta particle: one negative charge
Neutron: neutral, no charge
What was concluded from Ernest Rutherford's experiment - Answers That alpha particles when
shot at a metal target mostly passed through but some were deflected at large angles.
