Mix and Flow of Matter
What is a fluid?
A substance that can flow. A liquid or gas.
What structure is found in plant cells but not animal cells?
Cell wall or chloroplast
What is reflection?
The bouncing of light.
What is the pivot point of a lever called?
Fulcrum
What percentage of Earth's water is freshwater?
About 3%.
Name one factor that increases dissolving rate.?
Stirring, heating, or crushing into smaller pieces.
What structure surrounds the cell and controls what enters and leaves?
What law states that the angle of incidence equals the angle of reflection?
Law of reflection
When two gears mesh, what happens to their direction of rotation?
They rotate in opposite directions.
Name two sources of freshwater.
Lakes, rivers, glaciers, groundwater, wetlands.
What is a mixture?
Two or more substances physically combined.
Which body system breaks down food?
Digestive system
What is a luminous object?
An object that produces its own light.
What formula is used to calculate mechanical advantage?
MA = Load Force รท Effort Force.
Why are wetlands important?
They filter water and provide habitat for organisms.
What property describes how thick or resistant to flow a fluid is?
Viscosity
What is osmosis?
Movement of water through a membrane.
What is the function of the retina?
It detects light and sends signals to the brain.
What simple machine uses a grooved wheel and rope?
Pulley
What is a watershed?
An area of land that drains into a body of water.
What is the difference between a solute and a solvent?
The solute is dissolved; the solvent does the dissolving.
Which direction do particles move during diffusion?
What type of energy is light?
Electromagnetic energy
If a machine requires less effort force than the load force, does it have mechanical advantage greater than or less than 1?
Greater than 1.
A farmer applies fertilizer to a field beside a river. After a heavy rain, large amounts of algae begin growing in the river. Explain what likely happened and describe one impact on the ecosystem.
Fertilizer runoff entered the river, adding nutrients that caused an algal bloom. The algae can reduce oxygen levels in the water, harming fish and other aquatic organisms.