In terms of density, why does an egg sink in fresh water?
The egg is denser than fresh water
Objects sink in a fluid if they are denser than the fluid.
How can you increase the density of water?
By adding salt
Increasing the concentration of solutes raises the density of the solution.
What effect does depth have on pressure?
Pressure increases with depth
Every 10m of depth adds approximately 1 atm of pressure.
In our lab, what factors can we use to change the density of a water sample?
- Temperature
- Salinity
- Pressure
These factors can be manipulated to observe changes in density.
What happens to the oxygen in water when it gets warm?
Oxygen levels decrease
Warmer water holds less dissolved oxygen.
How can you make a raw egg float?
Add salt
Increasing the salinity of the water makes it denser than the egg.
Every 10m is equal to how many atmospheres?
1 atm
This is a standard measurement for pressure underwater.
What are the characteristics of the densest water?
- High temperature
- High salinity
Densest water is typically found in specific oceanic conditions.
What is the concentration of salts in fresh water?
0.5 ppt
Fresh water has a very low concentration of salts compared to salt water.
How is salinity expressed?
Ppt (parts per thousand)
Salinity measures the concentration of salts in water.
What environmental factors contribute to the salinity of water?
- Evaporation
- Precipitation
- Runoff
These factors influence the overall salinity levels in bodies of water.
What factors determine salinity?
- Evaporation increases salinity
- Precipitation decreases salinity
- Runoff decreases salinity
These processes affect the concentration of salts in water.
The pressure for organisms on land at sea level is?
1 atm
This is the standard atmospheric pressure at sea level.
The temperature ranges in the ocean from _____30c_____ to ____-2c____.
30°C to -2°C
These temperatures represent the extremes found in ocean waters.
What three factors can change the density of water?
- Temperature
- Salinity
- Pressure
Each factor can significantly alter the density of water.
What happens to salt water when you add it to a sample of fresh water?
Salt water sinks
Salt water is denser than fresh water, causing it to sink.
If two samples of water are layered on each other, which one would be fresh water and which one would be salt water?
Orange would be fresh water, green salt water
The denser salt water will layer beneath the less dense fresh water.
What contributes to DO (dissolved oxygen) levels in water?
- Temperature
- Salinity
- Pressure
These factors influence the amount of oxygen that can be dissolved in water.
How does adding salt affect the freezing point of water?
Lowering the freezing point
Salt causes the freezing point of water to decrease significantly.
Define density.
A mass of a given volume
High density means an object will sink, low density means it will float.
What is brackish water?
A mix of fresh and salt water
Brackish water typically occurs in estuaries.
What is a hydrometer?
An instrument for measuring the density of liquids
Hydrometers are commonly used in various scientific applications.
