Scientific Method
What is the first step scientists often take when beginning an investigation?
Observation
What variable is intentionally changed by the scientist?
Independent variable
What group provides a comparison for the experimental group?
Control group
When converting from a larger metric unit to a smaller metric unit, does the numerical value become larger or smaller?
Larger
What does kilo- mean?
1,000 or 10³
What is a testable prediction that can be investigated through an experiment?
Hypothesis
What variable is measured or observed during an experiment?
Dependent variable
What group receives the condition or treatment being tested?
Experimental group
When converting from a smaller metric unit to a larger metric unit, does the numerical value become larger or smaller?
Smaller
What does centi- mean?
0.01 or 10⁻²
What part of an experiment involves collecting measurements and observations?
Data
What are variables called that are kept the same throughout an experiment?
Controlled variables
A scientist tests a new fertilizer on plants but keeps water, sunlight, soil, and plant type the same. Why?
To control other variables
Convert 3 km to meters.
3,000 m
What does milli- mean?
0.001 or 10⁻³
What is the purpose of a conclusion?
Interpret the results and determine whether the evidence supports the hypothesis
A scientist changes temperature and measures reaction time. Identify the independent and dependent variables.
Independent: temperature; Dependent: reaction time
A control group receives no experimental treatment. Why is this useful?
It provides a baseline for comparison
Convert 4,500 mg to grams.
4.5 g
What does pico- mean?
0.000000000001 or 10⁻¹²
A scientist observes something unexpected and asks why it happened. What step comes after the observation?
Question
Why is changing multiple variables at the same time a problem in an experiment?
You cannot determine which variable caused the results
A student tests whether temperature affects reaction rate but uses different amounts of chemicals in each trial. What is wrong with the experiment?
More than one variable was changed
Convert 2.5 km to centimeters.
250,000 cm
What SI base unit represents the amount of substance in chemistry?
Mole (mol)
A mole in chemistry is a standard unit of measurement used to count tiny particles like atoms, molecules, or ions.
Counting by weighing: Because atoms are too small to count individually, chemists use moles to measure out exact amounts using a standard scale.