Adhesion, Cohesion, Surface Tension

Water Structure Chemical Formula H2O H2O molecules are held together by covalent bonds

Polarity Oxygen is “stronger/more greedy” than hydrogen. The O and H2 atoms share the electrons unequally which causes a + and – charge to appear on opposite ends of the H2O molecule.

Cohesion Cohesion = attraction between substances of the same kind. Hydrogen Bonding This attraction between H2O molecules causes a condition known as Surface Tension

Surface Tension High surface tension allows long H2O columns to be drawn from roots to leaves.

Adhesion Adhesion= an attraction between different substances and explains mutual attraction of polar molecules. Example: Capillary Action- the process of moving H2O molecules up a narrow tube.

Polarity & the Universal Solvent Polarity enables many substances to dissolve in H2O. Ionic Compounds & polar compounds can be dissolved in H2O. Example: Sodium Chloride (NaCl) Nonpolar molecules do not dissolve well in H2O Example: Oils