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3. Ions of Salt Dissolved in Seawater?

1. Introduction
2.  Salt in Seawater?
3. Ions of Salt
4. Source of the Salt?
5. Salinity Variability
6.Salinity & Precipitation
7. Salinity Summary
8. Calculating Salinity
9. Ocean Temperature
10. Solar Radiation
11. Properties
12. Light Penetration
13. Temperature
14. Thermocline
15. Density
16. Layering

The diagram below illustrates the concept of a dissolved salt where ions of Na⁺ and Cl^- are surrounded by a sea of H₂O molecules. 

The + and - superscripts denote the charge of each ion, which is controlled by the balance of electrons and protons contained in the ion.

Used with Permission of Matthias Tomczak ©Copyright 1997

1. Notice how the positive-charged ions of Na⁺ are attracted to the negative charged, O^2-(oxygen), side of the water molecule. Conversely, the Cl^- ion is attracted to the side of the H₂O molecule with the two Hydrogen ions with positive charges (H⁺).  

2. Why are some ions attracted to each other while  others are repelled from each other?

Remember that "opposite" charges attract and "like" charges repel -- so it has to do with the atomic charges of the respective ions (Na⁺ &  Cl^-) and the nature of the distribution of charges within the water molecule (H₂O).  The water molecule (H₂O) has a slightly positive charge on H⁺ side and slightly negative on the O^2- side of the water molecule.

Send to Don Reed
Department of Geology
San Jose State University

#1 What are the two most common ions associated with the salty taste of sea water?

a) Potassium (K⁺)
b) Chloride (Cl^-)
c) Sodium (Na⁺)
d) Both K⁺ and Cl^-
e) Both Cl^- and Na⁺