Question

how do chemical weathering, gas exchange, and limestone formation help marine organisms thrive? select all that apply. carbon from the shells and exoskeletons of marine organisms can be stored underground in limestone for millions of years. this prevents excessive buildup of co₂ in the atmosphere and ocean water. ca²⁺ ions primarily enter the oceans via runoff from chemical weathering. they combine with co₃²⁻ ions as marine organisms build their shells and exoskeletons. ocean chemistry is regulated in part by the exchange of co₂ gas between the atmosphere and the ocean. marine organisms break down caco₃ as they build their shells and exoskeletons. this process releases hco₃⁻ ions that make the ocean less acidic.

Explanation:

• Chemical weathering provides $Ca^{2+}$ ions for shell - building in marine organisms. Gas exchange regulates ocean chemistry by exchanging $CO_2$ between atmosphere and ocean. Limestone formation stores carbon from marine organisms' shells, preventing $CO_2$ buildup. Marine organisms do not break down $CaCO_3$ to make the ocean less acidic; rather, they use $Ca^{2+}$ and $CO_3^{2 - }$ to build shells.

Answer:

• Carbon from the shells and exoskeletons of marine organisms can be stored underground in limestone for millions of years. This prevents excessive buildup of $CO_2$ in the atmosphere and ocean water.
• $Ca^{2+}$ ions primarily enter the oceans via runoff from chemical weathering. They combine with $CO_3^{2 - }$ ions as marine organisms build their shells and exoskeletons.
• Ocean chemistry is regulated in part by the exchange of $CO_2$ gas between the atmosphere and the ocean.