Chemistry Basics Mrs. Mawhiney. There are two types of observations: Quantitative observations...
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Chemistry Basics Mrs. Mawhiney. There are two types of observations: Quantitative observations involve measurements or estimates that yield meaningful,
There are two types of observations: Quantitative observations
involve measurements or estimates that yield meaningful, numerical
results. Qualitative observations yield descriptive, nonnumerical
results.
Slide 3
Comparison of Qualitative and Quantitative Observations
Qualitative (words only)Quantitative (words and numbers) The girl
has very little money.The girl has 85 cents. The man is short.The
man is 5 feet 2 inches tall. Use a small test tube.Use a test tube
that is 12 centimeters long. It is a short walk to my house.It is
about 1 mile to my house. Quantitative and Qualitative Observations
Compared
Slide 4
How do we measure? The metric system is an international
decimal- based system of measurement. Because the metric system is
a decimal system, making conversions between different units of the
metric system are always done with factors of ten.
Slide 5
Slide 6
SI Units MeasurementUnitSymbol MassKilogramkg LengthMeterM
TimeSeconds TemperatureKelvinK QuantityMolemol EnergyJouleJ
PressurePascalPa
Slide 7
Mass and weight Whats the difference? The mass of an object is
a measure of the amount of matter in it. The basic unit of mass in
the International System of Units is the kilogram. The weight of an
object is the force of attraction between the object and the earth
(or whatever large, gravity-producing body the object is located
on).
Slide 8
No Calculator Vomit!!! In Science we use significant figures!
We like accuracy and precision!! 2732100000000000
Slide 9
Counting Significant Figures Atlantic / Pacific Method a.
Absent Decimal- Start on atlantic side of number & cross out
all zeroes until 1 st nonzero digit is reached, remaining digits
are significant b. Present decimal- start on the pacific side of
the number & cross out all zeros until the 1 st nonzero digit
Is reached, remaining digits are significant
Slide 10
How many significant figures are in each of the following
measurements? 24 mL2 significant figures 3001 g 4 significant
figures 0.0320 m 3 3 significant figures 6.400 x 10 4 molecules 4
significant figures 560 kg2 significant figures
Slide 11
Density
Slide 12
Density Demo After watching the demonstration, what can you
tell me about the reason ice floats on water. Ice is made up of
water right??
