1. In which state do two F atoms have lower energy, when they are
isolated atoms at a great distance from one another, or close to one
another in a F2
molecule? Is energy absorbed, or given off, when two F atoms join
to form a F2 molecule?
2. How does VSEPR theory explain the observed geometry of molecules
of methane, ammonia, and water?
3. If the central atom is represented by X, why does the H-X-H bond
angle decrease from 109.5 degrees in methane, to 107 degrees in ammonia,
to 105 degrees in water?
4. What kind of force or attraction makes methane condense from a
gas to a liquid at low temperatures? Why need the temperature not
be reduced as low for condensation to occur for methane as for hydrogen?
