1.0 Flashcards
(32 cards)
What percentage of Earth’s surface is covered with water?
74%
Earth is often referred to as the “water planet” or the “blue planet” due to its water coverage.
What is the term for water that humans can drink safely?
Potable water
Only a tiny amount of water on Earth is potable.
What is the percentage of salt water compared to fresh water on Earth?
Salt water: 97%, Fresh water: 3%
Of the fresh water, 77% is ice, 22% is groundwater, and 1% is in lakes, rivers, and wetlands.
How much of the Earth’s fresh water is locked in ice and not readily available for human use?
77%
Most of the fresh water is in icecaps and sea ice in the Arctic and Antarctic.
Fill in the blank: Only about ______ of all the water on Earth is available for humans to drink.
0.003%
This is a very small fraction of the total water supply.
What is salinity?
The total amount of all salts dissolved in water
Seawater has an average salinity of 3.5%.
True or False: Fresh water always contains harmful organisms.
False
While fresh water can contain organisms, not all are harmful.
What is hard water?
Water that contains a high concentration of calcium and magnesium
Hard water can affect soap lathering and leave mineral deposits.
How much of Earth’s fresh water is found in lakes, rivers, and wetlands?
1%
The majority of fresh water is either frozen or groundwater.
What is the average salinity of seawater?
3.5%
This salinity level is much higher than that of fresh water.
What is the role of water treatment processes?
To prevent harmful organisms from becoming a problem in drinking water
Effective treatment is essential for maintaining water quality.
What happens to water when it evaporates from samples?
It becomes gas in the atmosphere
About 0.0009% of all the water on Earth is in gas form at any time.
What is a reservoir?
An artificial lake used for water storage and management
Reservoirs can be used for drinking water, irrigation, and hydroelectricity generation.
What is the significance of the statement ‘If all the fresh water on Earth were in one glass’?
It illustrates the extremely small amount of accessible drinking water
This analogy helps to understand water scarcity.
What is the largest percentage of dissolved salts in seawater?
Sodium chloride (NaCl) at approximately 85%
Sodium chloride is the primary component of seawater.
What is the percentage of calcium in seawater?
1.2%
Calcium is one of the dissolved salts found in seawater.
What is the percentage of potassium in seawater?
1.1%
Potassium is another component of dissolved salts in seawater.
What is the importance of water quality testing?
To ensure water is potable and safe for human use
Water quality testing is crucial for public health.
Where do most towns and cities get their drinking water from?
Surface sources like lakes or rivers
Surface water may require filtration and chemical treatment.
What is the typical process for treating water from surface sources?
Filtering and treating with chemicals
This process ensures the water is safe for consumption.
What is Giardia?
A parasite that causes intestinal problems in humans
Giardia can be present in untreated water sources.
What materials are needed for the water testing inquiry activity?
- 500-mL sample of tap water
- 2 samples of untreated water
- filter paper
- funnel
- graduated cylinder
- test tubes
- silver nitrate
- Erlenmeyer flasks
- soap flakes
- bromothymol blue
These materials are essential for conducting various water quality tests.
What is the purpose of testing water clarity?
To observe differences in appearance before and after filtering
Clarity can indicate the presence of particulates or contaminants.
What is used to test for chlorine in water?
Silver nitrate solution
Silver nitrate reacts with chlorine to indicate its presence.
