CHEM 120 FINAL REVIEW EXAM
QUESTIONS AND ANSWERS GRADED A+
2025/2026
Significant figures - ANS a digit that is either reliably known or closely estimated
Significant Figure Rules - ANS 1. All non-zero digits are always significant
2. Zeroes between non-zero digits are always significant
3. Zeroes to left of first non-zero digit (either before or after decimal point) are never significant
4. Zeroes to the right of last non-zero digit
a. after decimal point are always significant
b. which are before decimal point are not significant
conversion factor - ANS relationship between two quantities expressed as a fraction
dimensional analysis - ANS conversion of a measurement in one unit into another by the use
of conversion factors
True - ANS T/F: number of protons never changes according to periodic table
number of protons - ANS atomic number=_______________________
number of neutrons - ANS mass number=_______________________
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, isotopes - ANS atoms with same number of protons (same electron) but different number of
neutrons
atomic mass - ANS weighted average of the isotopic masses of all stable isotopes of an
element
compound - ANS substance composed of 2+ elements that are chemically combined
molecular compound - ANS compound in which atoms are held together by covalent bonds
ionic bond - ANS nonmetal and metal (giving away of electrons by one and receiving by the
other); electrostatic interactions between positive and negative ions
covalent bond - ANS 2 nonmetals (sharing of bonds); the sharing of electrons between two
atoms
ion - ANS atom that has an electrostatic charge
cation - ANS positively charged atom
anion - ANS negatively charged atom
formula unit - ANS simplest whole number ratio of ions in ionic compound
polyatomic ion - ANS groups of covalently-bonded atoms that have an overall charge
physical change - ANS change in a substance that does not change its composition
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
QUESTIONS AND ANSWERS GRADED A+
2025/2026
Significant figures - ANS a digit that is either reliably known or closely estimated
Significant Figure Rules - ANS 1. All non-zero digits are always significant
2. Zeroes between non-zero digits are always significant
3. Zeroes to left of first non-zero digit (either before or after decimal point) are never significant
4. Zeroes to the right of last non-zero digit
a. after decimal point are always significant
b. which are before decimal point are not significant
conversion factor - ANS relationship between two quantities expressed as a fraction
dimensional analysis - ANS conversion of a measurement in one unit into another by the use
of conversion factors
True - ANS T/F: number of protons never changes according to periodic table
number of protons - ANS atomic number=_______________________
number of neutrons - ANS mass number=_______________________
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, isotopes - ANS atoms with same number of protons (same electron) but different number of
neutrons
atomic mass - ANS weighted average of the isotopic masses of all stable isotopes of an
element
compound - ANS substance composed of 2+ elements that are chemically combined
molecular compound - ANS compound in which atoms are held together by covalent bonds
ionic bond - ANS nonmetal and metal (giving away of electrons by one and receiving by the
other); electrostatic interactions between positive and negative ions
covalent bond - ANS 2 nonmetals (sharing of bonds); the sharing of electrons between two
atoms
ion - ANS atom that has an electrostatic charge
cation - ANS positively charged atom
anion - ANS negatively charged atom
formula unit - ANS simplest whole number ratio of ions in ionic compound
polyatomic ion - ANS groups of covalently-bonded atoms that have an overall charge
physical change - ANS change in a substance that does not change its composition
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
