Answer is sodium, Na, and magnesium, Mg
Hydrogen bonds are classified as weak because they are formed fast, but they also break easily under normal biological conditions.
Weak bonds can be easily broken, but this is extremely important because they are in bold in biological systems. For example, they help to decide and stabilize the shapes of water molecules.
The answer is light reactions
Carbon dioxide and oxygen are
differentially exchanged between the atmosphere and the oceans in the carbon
cycle. An increase in atmospheric carbon dioxide also raises the carbon dioxide
absorbed by the oceans. This increases the pH of the ocean waters which consequently
affects the growth of phytoplankton. Low pH affects negatively the growth of phytoplankton.
The clarity of the waters would, therefore, increase with pH due to low
plankton growth.