Question

Salts dissociate in aqueous solutions to release charged, inorganic atoms or molecules called ions. in biological systems, the most common of these functionally important ions are:

Answer 1

There are many important ions in the body, some of them are:
·     Sodium ions (Na+) are the main cations found outside cells which regulate and control the level of body fluids. Too much of this ion increases water retention, leading to high blood pressure (hypertension).
·     Potassium ions (K+)  are the principal cations found inside the which regulate cellular functions, including nerve impulses and heartbeats, and the level of body fluids.
·     Chloride ions (Cl-)  are the principal anions found outside cells in the body. Like sodium and potassium ions, chloride ions are involved in maintaining acid-base and fluid balances.
·     Calcium ions (Ca+) occur mainly in the skeleton and therefore it is essential for building and maintaining bones and teeth. Also,  plays a crucial role in muscle contraction, and the transmission of nerve signals to cells. 

Answer 2

The most important ions would be sodium, calcium, and potassium

Sodium and potassium are the main ions that have a big role in the action potential. Calcium also has a role in muscle contraction. If their level is altered too much, the nervous and muscle system will be greatly disrupted and the effect could be life-threatening. Phosphate and magnesium also have a role in other mechanisms but less important than those 3