CHEM 111 Final Exam UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS
Sig Fig Rules 1. All non zero- digits and zeros between non-zeros are significant
2. Zeroes at the beginning are not significant
3. At the end zeroes are significant if there is a decimal point and they are not
significant
if there is no decimal point.
Adding/Subtracting Sig Figs final answer is given the same number of decimal points as the number with the
fewest decimal places
Multiplying/Dividing Sig Figs final answer is given the same number of sig figs as the value with the fewest sig
figs
Precise Measurements repeated measurements are very close to each other
Accurate Measurements repeated measurements are close to the true value
Element the most basic unit of matter, composed of only one type of atom and cannot be
broken down
Atoms smallest chemical unit of matter or indivisible unit of an element
Molecule formed when 2 or more atoms join together chemically
Compounds at least 2 or more atoms of different elements combined
Are all molecules also compounds? All compounds are molecules but not all molecules are compounds
, Pure Substance has the same chemical composition throughout, only consists of 1 element or a
single compound, cannot be separated
Homogenous Mixture mixtures that are uniform and have the same composition
Heterogenous Mixture composition is not uniform, easier to separate components
Solid State molecules closely packed, strong molecular interaction, least amount of kinetic
energy
Liquid State molecules intermediately packed, intermediate molecular interaction, and
intermediate kinetic energy
Gas State molecules widely spaced, weak molecular interaction, greatest amount of kinetic
energy
Physical Changes do not change the chemical composition
Examples of Physical Properties density, color, melting point, boiling point, condensation, evaporation, dissolution
Chemical Changes a change in the chemical composition
Examples of Chemical Properties reactivity with other compounds, combustion
Mega-prefix (M) factor of 10^6
Kilo-prefix (k) factor of 10^3
Deci-prefix (d) factor of 10^-1
Centi-prefix (c) factor of 10^-2
Milli-prefix (m) factor of 10^-3
Micro-prefix (m) factor of 10^-6
Nano-prefix (n) factor of 10^-9
Pico-prefix (p) factor of 10^-12
Density and Floating density explains why ice can float on water, higher density sinks and lower density
floats
Atomic Number number of protons in an element
Mass Number total number of protons and neutrons
Proton +1, in the nucleus
Sig Fig Rules 1. All non zero- digits and zeros between non-zeros are significant
2. Zeroes at the beginning are not significant
3. At the end zeroes are significant if there is a decimal point and they are not
significant
if there is no decimal point.
Adding/Subtracting Sig Figs final answer is given the same number of decimal points as the number with the
fewest decimal places
Multiplying/Dividing Sig Figs final answer is given the same number of sig figs as the value with the fewest sig
figs
Precise Measurements repeated measurements are very close to each other
Accurate Measurements repeated measurements are close to the true value
Element the most basic unit of matter, composed of only one type of atom and cannot be
broken down
Atoms smallest chemical unit of matter or indivisible unit of an element
Molecule formed when 2 or more atoms join together chemically
Compounds at least 2 or more atoms of different elements combined
Are all molecules also compounds? All compounds are molecules but not all molecules are compounds
, Pure Substance has the same chemical composition throughout, only consists of 1 element or a
single compound, cannot be separated
Homogenous Mixture mixtures that are uniform and have the same composition
Heterogenous Mixture composition is not uniform, easier to separate components
Solid State molecules closely packed, strong molecular interaction, least amount of kinetic
energy
Liquid State molecules intermediately packed, intermediate molecular interaction, and
intermediate kinetic energy
Gas State molecules widely spaced, weak molecular interaction, greatest amount of kinetic
energy
Physical Changes do not change the chemical composition
Examples of Physical Properties density, color, melting point, boiling point, condensation, evaporation, dissolution
Chemical Changes a change in the chemical composition
Examples of Chemical Properties reactivity with other compounds, combustion
Mega-prefix (M) factor of 10^6
Kilo-prefix (k) factor of 10^3
Deci-prefix (d) factor of 10^-1
Centi-prefix (c) factor of 10^-2
Milli-prefix (m) factor of 10^-3
Micro-prefix (m) factor of 10^-6
Nano-prefix (n) factor of 10^-9
Pico-prefix (p) factor of 10^-12
Density and Floating density explains why ice can float on water, higher density sinks and lower density
floats
Atomic Number number of protons in an element
Mass Number total number of protons and neutrons
Proton +1, in the nucleus
