Normal optical microscopes use a visible light source, glass lenses and the image can be detected by the human eye.

 If the solution of problem 37 is added to an aqueous solution of barium chloride, a precipitate

      forms. Provide the net ionic reaction for this precipitate formation.

4.  Ozone, O3, is a component of photochemical smog in the lower atmosphere but essential in

       the upper atmosphere where it absorbs harmful UV radiation which would otherwise burn us.

       Using (a) drawing(s) discuss the molecular geometry of ozone being sure to address

       comparative bond lengths, approximate bond angle and dipole moment direction.

5.  The HCH bond angle in methane (CH4) is 109.5° the HNH bond angle in ammonia (NH3) is 107°

      and the HOH bond angle in water is 104.5°. Why the decrease in the idealized tetrahedral bond

      angle of 109.5° in going from methane to ammonia to water?