Chem 280 midterm questions with 100%
complete solutions passed|| GRADED
A+|| LATEST UPDATE 2026
Define Chemistry: -CORRECTANSWER Science that tries to understand how matter
behaves by studying how atoms / molecules behave
Scientific Method / steps -CORRECTANSWER A way of learning that emphasizes
observation/experimentation to understand the world.
1. observation
2. form hypothesis
3. test hypothesis by experiment
4. form law/theory
Observations -CORRECTANSWER measurement of some aspect of nature
- some simple w/ naked eye, others rely on sensitive instrumentation
- occasionally observation happens by chance
- usually involves measurement/description of some aspect of physical world
Hypothesis -CORRECTANSWER tentative interpretation or explanation of observation
-good hypothesis is falsifiable -> further testing has potential to prove it wrong
, Experiment -CORRECTANSWER highly controlled observations designed to validate or
invalidate hypothesis
- these results may confirm or show hypothesis to be wrong
- hypothesis may have to be modified or discarded/replaced
- leads to scientific law
Scientific Law -CORRECTANSWER Brief statement that summarizes past observations
and predicts future ones
The Law of Conservation of Mass. -CORRECTANSWER All matter in chemical reaction
is neither created nor destroyed
Theory -CORRECTANSWER one or more well-established hypothesis may for basis for
scientific theory
- theories provide broader/deeper explanation for observations + laws.
- they model nature + predict behavior that extends well beyond observations/laws on
which they are founded
- atomic theory: all matter composed of small, indestructible particles = atoms
What is the correct multiplier for the prefix centi? -CORRECTANSWER 10-2
What is the correct scientific notation and total number of sig figs for 0.00032400? -
CORRECTANSWER 3.2x10-4
complete solutions passed|| GRADED
A+|| LATEST UPDATE 2026
Define Chemistry: -CORRECTANSWER Science that tries to understand how matter
behaves by studying how atoms / molecules behave
Scientific Method / steps -CORRECTANSWER A way of learning that emphasizes
observation/experimentation to understand the world.
1. observation
2. form hypothesis
3. test hypothesis by experiment
4. form law/theory
Observations -CORRECTANSWER measurement of some aspect of nature
- some simple w/ naked eye, others rely on sensitive instrumentation
- occasionally observation happens by chance
- usually involves measurement/description of some aspect of physical world
Hypothesis -CORRECTANSWER tentative interpretation or explanation of observation
-good hypothesis is falsifiable -> further testing has potential to prove it wrong
, Experiment -CORRECTANSWER highly controlled observations designed to validate or
invalidate hypothesis
- these results may confirm or show hypothesis to be wrong
- hypothesis may have to be modified or discarded/replaced
- leads to scientific law
Scientific Law -CORRECTANSWER Brief statement that summarizes past observations
and predicts future ones
The Law of Conservation of Mass. -CORRECTANSWER All matter in chemical reaction
is neither created nor destroyed
Theory -CORRECTANSWER one or more well-established hypothesis may for basis for
scientific theory
- theories provide broader/deeper explanation for observations + laws.
- they model nature + predict behavior that extends well beyond observations/laws on
which they are founded
- atomic theory: all matter composed of small, indestructible particles = atoms
What is the correct multiplier for the prefix centi? -CORRECTANSWER 10-2
What is the correct scientific notation and total number of sig figs for 0.00032400? -
CORRECTANSWER 3.2x10-4
