WTCC CHM 151 EXAM 1 QUESTIONS WITH VERIFIED SOLUTIONS LATEST UPDATE 2026
Chemistry - Answers The study of the compositions, properties, and interactions of matter
Matter - Answers anything that occupies a volume and has a mass
Atom - Answers smallest particle of an element that has the properties of that element
Molecules - Answers two or more atoms joined by strong forces called chemical bonds
Hypothesis - Answers Tentative explaination for observations
guess or prediction of why something happens (must be testable)
if, then, because statements
Theory - Answers really strong hypothesis w/ lots of evidence
still explains why
1st Domain of chemistry - Answers Macroscopic (can see w/ eyes)
2nd Domain of chemistry - Answers Microscopic (really small, can see with microscope)
3rd Domain of Chemistry - Answers Symbolic (symbols that represent states of matter)
solids - Answers do not conform to the shape of their container
liquids - Answers conform to the shape of their container
gases - Answers assume both the shape and volume of their container
Pure Substance - Answers has definite compositions and properties, cannot be physically seperated
- Element + Compound
Element (Pure subs) - Answers A pure substance made of only one kind of atom
cant be broken down chemically into simpler substances
Compound (pure subs) - Answers substance formed by the chemical combination of two or more
atoms, can be broken down chemically
Mixtures - Answers can be physically seperated
can be hetero/homogenous
heterogenous (mixt.) - Answers Non-uniform (can see different parts with eyes.)
homogenous (mixt) - Answers uniform (cant see different parts with eyes)
physical properties - Answers -type of substance does NOT change
-Atoms or molecules are still the same composition
-location in space or energy of those atoms or molecules may change ex: (H20 (s) --> H20 (l) melting
chemical properties - Answers -type of substance does change
-atoms are rearranged
-ex: H20 --> H2 + O2 hydrogen gas into oxy gas through electricity
Physical changes and Properties - Answers melting, boiling, etc
color, density, hardness
chemical changes and properties - Answers digestion, combustion, oxidation
flammabiability, acidity, corrosiveness
Extensive Property - Answers Depends on the amount of matter present
ex: mass, volume, length, heat
Intensive Property - Answers Does not depend on the amount of matter
ex: temp, density
Quantitive - Answers measured and expressed with a number
includes a unit
Qualitative - Answers do not require measurement
based on observation
Mass - Answers measures the amount of matter
weight - Answers measures the gravitational attraction
Rules for sigfigs (6) - Answers 1) All nonzero numbers are significant
2) Zeroes between nonzero numbers are significant
3) Leading Zero's are never significant
4) zeros to the right of nonzero digits in numbers that include a decimal point are significant
5) zeros to the right of nonzero digits in numbers without decimals are amibigous for sigfigs
Rounding in add/subs - Answers round decimal to the number of decimal positions with fewest
decimal places
Rounding in mult/div - Answers round answer to the same number of sigfigs as the value with the
fewst sigfigs
Accuracy - Answers how close your value is to the true or accepted value
Chemistry - Answers The study of the compositions, properties, and interactions of matter
Matter - Answers anything that occupies a volume and has a mass
Atom - Answers smallest particle of an element that has the properties of that element
Molecules - Answers two or more atoms joined by strong forces called chemical bonds
Hypothesis - Answers Tentative explaination for observations
guess or prediction of why something happens (must be testable)
if, then, because statements
Theory - Answers really strong hypothesis w/ lots of evidence
still explains why
1st Domain of chemistry - Answers Macroscopic (can see w/ eyes)
2nd Domain of chemistry - Answers Microscopic (really small, can see with microscope)
3rd Domain of Chemistry - Answers Symbolic (symbols that represent states of matter)
solids - Answers do not conform to the shape of their container
liquids - Answers conform to the shape of their container
gases - Answers assume both the shape and volume of their container
Pure Substance - Answers has definite compositions and properties, cannot be physically seperated
- Element + Compound
Element (Pure subs) - Answers A pure substance made of only one kind of atom
cant be broken down chemically into simpler substances
Compound (pure subs) - Answers substance formed by the chemical combination of two or more
atoms, can be broken down chemically
Mixtures - Answers can be physically seperated
can be hetero/homogenous
heterogenous (mixt.) - Answers Non-uniform (can see different parts with eyes.)
homogenous (mixt) - Answers uniform (cant see different parts with eyes)
physical properties - Answers -type of substance does NOT change
-Atoms or molecules are still the same composition
-location in space or energy of those atoms or molecules may change ex: (H20 (s) --> H20 (l) melting
chemical properties - Answers -type of substance does change
-atoms are rearranged
-ex: H20 --> H2 + O2 hydrogen gas into oxy gas through electricity
Physical changes and Properties - Answers melting, boiling, etc
color, density, hardness
chemical changes and properties - Answers digestion, combustion, oxidation
flammabiability, acidity, corrosiveness
Extensive Property - Answers Depends on the amount of matter present
ex: mass, volume, length, heat
Intensive Property - Answers Does not depend on the amount of matter
ex: temp, density
Quantitive - Answers measured and expressed with a number
includes a unit
Qualitative - Answers do not require measurement
based on observation
Mass - Answers measures the amount of matter
weight - Answers measures the gravitational attraction
Rules for sigfigs (6) - Answers 1) All nonzero numbers are significant
2) Zeroes between nonzero numbers are significant
3) Leading Zero's are never significant
4) zeros to the right of nonzero digits in numbers that include a decimal point are significant
5) zeros to the right of nonzero digits in numbers without decimals are amibigous for sigfigs
Rounding in add/subs - Answers round decimal to the number of decimal positions with fewest
decimal places
Rounding in mult/div - Answers round answer to the same number of sigfigs as the value with the
fewst sigfigs
Accuracy - Answers how close your value is to the true or accepted value
