Experimental Design
What variable is purposely changed by the scientist?
Independent variable
What property describes water molecules attracting other water molecules?
Cohesion
What two elements make up a water molecule?
Hydrogen and oxygen
What do scientists collect during an experiment?
Data
What variable is measured in an experiment?
Dependent variable
What property describes water sticking to another substance?
Adhesion
What is the chemical formula for water?
H₂O
What is the first step in the scientific method?
Observation
What is a testable prediction called?
Hypothesis
What allows water to form a mound on a penny?
Cohesion, Surface tension
Is a water molecule polar or nonpolar?
Polar
A student says, "If water temperature increases, sugar will dissolve faster." What type of statement is this?
Hypothesis
A student changes the amount of sunlight a plant receives and measures its height. What is the dependent variable?
Plant height
Name the 3 water properties we've studied in the penny Lab
Cohesion, Adhesion and surface tension
Water called a "universal __________"?
Solvent
A student discovers that warmer water dissolves sugar faster. What should they do after analyzing the data?
Draw a conclusion.
A student tests three brands of paper towels. Each towel is the same size and receives the same amount of water. Name the independent variable and one controlled variable.
IV: brand of paper towel; Controlled: size or amount of water
The most drops of which liquid on the penny
Water
How does water's polarity help it dissolve substances?
The positive and negative regions of water attract charged or polar particles.
Why do scientists conduct multiple trials?
To increase the validity of the results