Lab 1: The Metric System & the Scientific Method Flashcards
hypothesis
A proposed explanation for a phenomenon/ an educated guess.
ex: Every time I eat something with peanuts I break out in hives. Therefore, I must be allergic to peanuts.
variable
Factors in an experiment
experimental group
The group in the experiment that has a changed variable that will later be compared to the control group, to find if the hypothesis is correct.
standardized variable
Factors and conditions that you try to keep the same among both the control and experimental groups
International System of Units (S.I.)
Another name for the metric system
gram
Metric base unit for mass
milli-
A thousandth of a base unit
1 meter = 1,000 millimeters
exponent
Represents the power of ten
kilo-
A thousand of a base unit
1 kilometer = 1,000 meters
pipettes
A slender tube attached to a bulb that is used for transferring or measuring out small quantities of liquid (volume)
taring
Subtracting the (gross) weight of the substance being measured from the container holding it, in order to get the weight of the substance only.
prediction
A statement about what will or may happen during the experiment
independent variable
The factor under study
control group
The group in the experiment that doesn’t have any variables changed. Used to compare with the experimental group. (placebo group)
sampling error
Occurs when you collect data from only part of a population because you only have an estimate of the true value
(ex: You want to know if all chickens can swim, but you tested only 10 chicken and based your observations on the whole chicken population.)
S.I.
Internation System of Units
Be able to use standardized metric units for volume, mass, and length.
Volume: liters (L)
Mass: grams (g)
Length: meters (m)
Erlenmeyer flask
A conical, flat-bottomed laboratory flask with a narrow neck used for measuring volume
meniscus
The curved upper surface of a liquid in a tube
theory
Underlying principles of science that are sustained by prediction and experimentation.
A theory is respected and generally considered to be “true” if it has been continually tested, but never falsified.
Ex: The theory of gravity
dependent variable
The factor that is measured or counted
“Outcome variable”
repetition
Obtaining the same results after several different experiments
metric
A system of standard measurement used by the scientific and medical community
graduated cylinder
A measuring cylinder used to measure the volume of a liquid.
pi-pump
A one-handed control pump used on pipets to measure the volume of liquid
Explain the process of the scientific method.
- Observations or measurements
- Questions
- Hypothesis
- Prediction
- Experiment
- Substantiated hypothesis
- New/Revised hypothesis
- New experiment
Identify the dependent, independent and controlled (standardized) variables in experiments.
Dependent variable- the variable that is changed
Independent variable-the variable that is measured
Controlled (standardized) variable- the variable that remains the same throughout the experiment
Know the difference between accuracy and precision.
Accuracy refers to how close the measurement you obtained is from the “true” value.
Precision is how often you get that measurement
You can have great precision but not be accurate.
Name and describe the standard metric units for volume, mass, temperature, and length.
Volume = liters (L) Mass = grams (g) Temperature = Celsius (°C)
Identify the control group in the an experiment and know the difference between a control group and a variable.
Control group is the group in an experiment that does not have a variable (factor) tested and is then used as a benchmark to measure how the experimental group (changed variable) did.
Know the meaning of the metric prefixes (centi-, milli-, micro-, and nano-) and use them with metric units.
Centi- is a hundredth of the base unit
(ex: 1 meter = 100 centimeters)
Milli- is a thousandth of the base unit
(ex: 1 meter= 1,000 millimeters)
Micro- is a millionth of the base unit
(ex: 1 meter = 1,000,000 micrometers)
Nano- is a billionth of the base unit
(ex: 1 meter = 1,000,000,000 nanometers)
Know the meaning of the metric prefixes (kilo-, mega-, and giga-) and use them with metric units
Kilo- is a thousand base units
(ex: 1 kilogram = 1,000 grams)
Mega- is a million base units
(ex: 1 megagram = 1,000,000 grams)
Giga- is a billion base units
(ex: 1 gigagram = 1,000,000,000 grams)
beaker
Glassware used to measure a liquid’s volume
Scientific Notation
Is the way that scientists easily handle very large numbers or very small numbers.
Ex. instead of writing 0.0000000056, we write 5.6 x 10-9.
meter (m)
Metric unit used to measure length
micro-
Micro- is a millionth of the base unit
ex: 1 meter = 1,000,000 micrometers
accuracy
How close the measurement is to the true value
liter (L)
Metric unit of measurement used for volume
degrees Celsius (°C)
Metric unit of measurement used for temperature
0 °C = 32 °F
centi-
A hundredth of a base unit
ex. 1 meter = 100 centimeters
nano-
A billionth of a base unit
ex. 1 meter = 1,000,000,000 nanometers
precision
How consistently a measurement can be reproduced
