Chem - Ch 1 + 3 Flashcards
What is the scientific method
a logical, Systematic approach to the solution of a problem
What is chemistry
the study of the composition of matter and the changes that matter undergoes
What is an observation
when you use your senses to obtain information
an observation can lead to a question
What is an interpretation
information acquired through observing something and then using prior knowledge to make a conclusion about it
What is a hypothesis
a proposed explanation for an observation
What is an experiment
a procedure that is used to test a hypothesis
What is the independent variable
the variable that you change during an experiment
also called the manipulated variable
What is the dependent variable
the variable that is observed during the experiment
also called the responding variable
What is a model
a representation of an object or an event when doing a difficult/impossible experiment (like w atoms)
What is a theory
a well-tested explanation for a broad set of observations
What is a scientific law
a concise statement that summarizes the results of many observations and experiments
Do the steps of the SM always have to be followed in order
no because you can do different parts of it multiple times before you even do one step (4 hypotheses/experiments before 1 theory)
What is the difference between a theory and a law
a law states a fact, and a theory tries to explain why that fact occurs
What is the difference between the world’s meaning of the word theory and the scientific meaning
The world takes it to really mean hypothesis, but scientifically it’s very reliable. There is a possibility that a theory may need to be changed at some point in the future to explain new observations/results
What is the difference between a theory and a hypothesis
[insert definitions of both] + a theory is basically a repeatedly well tested hypothesis that covers a large range of observations
What is the metric system based on
powers of 10
What is 1 mL the same as
1 cm3
What is temperature
a measure of how hot or cold an object is
What is density
the ratio of the mass of an object to its volume
How can 4 10g objects have different volumes?
if the 4 objects have different densities
Does the density of a substance depend on the size of the sample
no, density only depends on the composition of a substance, no on the size of the sample
What happens to the density of a substance as temperature increases
the density decreases
What is the equation for density
d = m/v
What is the equation for slope
rise over run
y1 - y2 over x1 -x2
What do the slopes represent
The density of our objects
Are the slopes different for our two sets of objects, why or why not?
Yes, because the masses and volumes (and therefore, densities) are different in each set, which would make the slopes different
What are good experiment errors
- estimating water levels wrong
- object wet before u weigh it
- wet fingers
- not checking water level each time
- splashing water
How do you think that type of container used to measure volume affected your results
Some containers are more precise than others (graduated cylinder vs beaker, for example), so depending on the type of container you used, your results could be more or less accurate
Which of your objects is most dense? How do you know?
Whichever one had bigger slope (since slope was the average densities of each object)
As the density of a substance increases, the volume of a given mass of that substance…
Decreases
If there is uncertainty in your measurements, how will your points fit the slope?
They won’t fit very well
