PRINCIPLES OF CHEMISTRY 1
UNIVERSITY OF IOWA FINAL
WITH 100% CORRECT ANSWERS
GRADED A+ (2026 UPDATE!!)
Sig Figs - answer-1) All nonzero digits are significant
2) zeroes between nonzero digits are always significant
3)zeroes at the beginning of a number are never significant
4)zeros at the end of the number are significant if the number contains a decimal point.
adding and subtracting sig figs - answer-same number of decimal places as the
measurement with fewest decimal places.
50.61+4.338+208.2= 263.148
sooo... 263.1
multiplying and dividing sig figs - answer-same number of sig figs as the measurement
with fewest sig figs
6.221 x 5.2= 32.3492
sooo... 32
Empedocles - answer-Q: Are there fundamental Substances?
A: yes, air, fire, water
Democritus - answer-Q: Is matter continuous or particulate?
A: Particulate ("atom" from Greek atomos= indivisible)
John Dalton - answer-Daltons Atomic Theory
1) All matter consists of tiny indivisible atoms.
,2) Atoms of an element are identical, but different from those other elements
3) Atoms of one element cannot be converted into those of another element.
4) Compounds result from chemical combinations of different elements; atom ratios
are integers.
Law Of Conservation of Mass - answer-mass of one side of the equation equals mass of
the other side
Law of Constant Composition - answer-In a compound the relative numbers and kinds
of atoms are constant ex: water is always H2O
Law of Multiple Proportions - answer-ratios are small whole numbers
Are John Dalton's Postulates always true? - answer-Nope!
-isotopes exist etc.
J.J Thomson - answer--cathode rays are independent of the electrode material
-Cathode rays are streams of negatively charged particles (now called electrons)
Robert Millikan - answer-Oil Drop experiment
-caused oil drops to become charged and observed their behavior in an electric
field.This led to charge of electron
Thomson's Plum Pudding Model - answer-Evenly distributed mass and positive charge
(cookie)
Small embedded negative particles (chocolate chips)
Ernest Rutherford - answer-discovered nature of radioactivity
, Proposed nuclear atom as:
-very small, dense, positive nucleus
-surrounded by negative electrons
Rutherford's Gold Foil experiment - answer-studied angles at which alpha particles
were scattered after passing through thin gold foil
-disproved plum pudding modelof atom
Isotopes - answer-atoms with identical atomic numbers (same number of protons) but
different mass numbers (different # of neutrons)
-atomic number (z)= number of protons
-mass number (A)= number of protons+ neutrons
atomic mass - answer-mass of a single atom in atomic mass units (amu)
mass spectrometer - answer-instrument that can determine very accurate mass
measurements and isotopic abundance
atomic weight - answer-average atomic mass of all of the isotopes of an element
weighted by the relative abundance of each isotope expressed in amu.
The seven diatomic molecules - answer-H,O,N,F,Cl,Br,I
Molecular Compound - answer-contain only non metals of metalloids
Ions - answer-formed when atoms gain or lose electrons
cation - answer-positive ion formed when electrons are lost
UNIVERSITY OF IOWA FINAL
WITH 100% CORRECT ANSWERS
GRADED A+ (2026 UPDATE!!)
Sig Figs - answer-1) All nonzero digits are significant
2) zeroes between nonzero digits are always significant
3)zeroes at the beginning of a number are never significant
4)zeros at the end of the number are significant if the number contains a decimal point.
adding and subtracting sig figs - answer-same number of decimal places as the
measurement with fewest decimal places.
50.61+4.338+208.2= 263.148
sooo... 263.1
multiplying and dividing sig figs - answer-same number of sig figs as the measurement
with fewest sig figs
6.221 x 5.2= 32.3492
sooo... 32
Empedocles - answer-Q: Are there fundamental Substances?
A: yes, air, fire, water
Democritus - answer-Q: Is matter continuous or particulate?
A: Particulate ("atom" from Greek atomos= indivisible)
John Dalton - answer-Daltons Atomic Theory
1) All matter consists of tiny indivisible atoms.
,2) Atoms of an element are identical, but different from those other elements
3) Atoms of one element cannot be converted into those of another element.
4) Compounds result from chemical combinations of different elements; atom ratios
are integers.
Law Of Conservation of Mass - answer-mass of one side of the equation equals mass of
the other side
Law of Constant Composition - answer-In a compound the relative numbers and kinds
of atoms are constant ex: water is always H2O
Law of Multiple Proportions - answer-ratios are small whole numbers
Are John Dalton's Postulates always true? - answer-Nope!
-isotopes exist etc.
J.J Thomson - answer--cathode rays are independent of the electrode material
-Cathode rays are streams of negatively charged particles (now called electrons)
Robert Millikan - answer-Oil Drop experiment
-caused oil drops to become charged and observed their behavior in an electric
field.This led to charge of electron
Thomson's Plum Pudding Model - answer-Evenly distributed mass and positive charge
(cookie)
Small embedded negative particles (chocolate chips)
Ernest Rutherford - answer-discovered nature of radioactivity
, Proposed nuclear atom as:
-very small, dense, positive nucleus
-surrounded by negative electrons
Rutherford's Gold Foil experiment - answer-studied angles at which alpha particles
were scattered after passing through thin gold foil
-disproved plum pudding modelof atom
Isotopes - answer-atoms with identical atomic numbers (same number of protons) but
different mass numbers (different # of neutrons)
-atomic number (z)= number of protons
-mass number (A)= number of protons+ neutrons
atomic mass - answer-mass of a single atom in atomic mass units (amu)
mass spectrometer - answer-instrument that can determine very accurate mass
measurements and isotopic abundance
atomic weight - answer-average atomic mass of all of the isotopes of an element
weighted by the relative abundance of each isotope expressed in amu.
The seven diatomic molecules - answer-H,O,N,F,Cl,Br,I
Molecular Compound - answer-contain only non metals of metalloids
Ions - answer-formed when atoms gain or lose electrons
cation - answer-positive ion formed when electrons are lost
