1. Water molecules each consist of 1 oxygen (O) and 2 hydrogen (H) atoms. O HH Figure 2.14 Water Molecules Surround Ions

2. The H 2 O molecule is asymmetrically constructed. Figure 2.14 Water Molecules Surround Ions

3. Because of this asymmetry, there is a slight residual charge at both poles of the molecule. The oxygen end retains a slight negative electrical charge... and the hydrogen end retains a slight positive electrical charge. -- ++ ++ Figure 2.14 Water Molecules Surround Ions

4. The ionic bonds between Na + and Cl - hold the ions together in a solid crystal. Figure 2.14 Water Molecules Surround Ions

5. However, when NaCl is dissolved in water... Figure 2.14 Water Molecules Surround Ions

6. ...the cation (Na + ) attracts the negative pole of water......and the anion (Cl - ) attracts the positive pole of water. Figure 2.14 Water Molecules Surround Ions

7. Thus, the NaCl molecule dissolves. Figure 2.14 Water Molecules Surround Ions

8. The dissolved ions are not able to reassociate into a solid. Figure 2.14 Water Molecules Surround Ions