Salinity and Water Composition Concepts

The video explains why the ocean is salty, detailing the process of rainwater dissolving carbon dioxide to form carbonic acid, which erodes rocks and creates ions. These ions are transported by rivers to the ocean. Sodium and chloride ions are prevalent, making seawater salty. Over time, the ocean's salinity has increased due to continuous ion deposition. Rivers contribute significantly by carrying dissolved solids to the ocean. The salinity of seawater is about 3.5%, and if spread over land, the salt would form a thick layer.

What causes rainwater to become slightly acidic?

• Dissolved carbon dioxide

• Dissolved nitrogen

• Dissolved hydrogen

• Dissolved oxygen

What are the two most prevalent ions in seawater?

• Calcium and magnesium

• Potassium and sulfate

• Sodium and chloride

• Bicarbonate and carbonate

How do organisms in the ocean affect the concentration of dissolved ions?

• They increase the concentration by releasing ions

• They convert ions into other elements

• They use some ions, reducing their concentration

• They do not affect the concentration

Why don't rivers and streams taste salty?

• They are too small to hold salt

• They are replenished by fresh rainwater

• They have a natural filtering system

• They flow too quickly to accumulate salt

What is the average salinity of seawater?

• 40 parts per thousand

• 35 parts per thousand

• 30 parts per thousand

• 25 parts per thousand

If ocean salt were spread over the Earth's land surface, how thick would the layer be?

• 1000 feet

• 100 feet

• 500 feet

• 200 feet

What is the estimated annual amount of dissolved solids carried to the ocean by rivers?

• 4 billion tons

• 5 billion tons

• 3 billion tons

• 2 billion tons