Unique Nature of Pure Water
Physical Properties of Sea Water
Chemical Properties of Sea Water
Ocean Acidification
Carbon Cycle
100


  • What type of bond holds water molecules together?


Hydrogen bond


100


  •  What is the average salinity of ocean water?



  • About 35 parts per thousand (ppt).


100


  • What are the two most common ions in seawater?



  • Sodium (Na⁺) and chloride (Cl⁻).


100


  • What gas causes ocean acidification when absorbed by seawater?



  • Carbon dioxide (CO₂).


100


  • What is the main form of carbon in the atmosphere?



  • Carbon dioxide (CO₂).


200


  • What is the term for water molecules sticking to each other?


  • Answer: What is cohesion?



  • Cohesion


200


  • What two factors most affect seawater density?



  • Temperature and salinity.


200


  • What process keeps the proportions of dissolved elements constant?



  • The rule of constant proportions.


200


  • What acid forms when CO₂ mixes with seawater?



  • Carbonic acid (H₂CO₃).


200


  • What process by plants removes CO₂ from the atmosphere?



  • Photosynthesis


300


  • Why does ice float on water?



  • Because solid water is less dense than liquid water.


300


  • Why does cold, salty water sink below warm, fresh water?



  • Because it is denser.


300


  • What happens to oxygen levels with increasing depth?



  • They generally decrease due to less photosynthesis and more respiration.


300


  • How does ocean acidification affect marine shells and corals?



  • It dissolves calcium carbonate structures.


300


  • How does the ocean act as a carbon sink?



  • It absorbs and stores large amounts of CO₂.


400


  • What allows water to dissolve so many substances?



  • Its polarity


400


  • How does evaporation affect salinity?



  • It increases salinity by removing pure water and leaving salts behind.


400


  • How does salinity affect freezing point?



  • Higher salinity lowers the freezing point of seawater.


400


  • What happens to ocean pH as more CO₂ dissolves?



  • It decreases (becomes more acidic).


400


  • What role do marine organisms play in the carbon cycle?



  • They use carbon to build shells and skeletons.


500


  • How does hydrogen bonding affect water’s specific heat?



  • It gives water a high specific heat, allowing it to resist temperature change.


500


  • What is a thermocline?



  • A layer of rapid temperature change with depth in the ocean.


500


  • Why is seawater slightly basic (around pH 8)?



  •  Because dissolved carbonates act as buffers.


500


  • Why is ocean acidification considered harmful to marine ecosystems?



  • It disrupts food chains and weakens coral reefs.


500


  • How does burning fossil fuels impact the carbon cycle?



  • It adds excess CO₂, enhancing the greenhouse effect and ocean acidification.