[bmgriffin]

If a solution of potassium fluoride is shaken with a solution of methylene chloride will a color change for methylene chloride layer be expected? Please explain why the electron affinity for chlorine is greater. I know it come first on the periodic table but I am not sure the actual reason. and last but not least; based on the electron configuration explain why members of a chemical family have similar chemical properties...Have mercy on me O Chemistry Forum for I am but a lowly student of botany and do not understand such things.

[Schrödinger]

Electron affinity for Cl is not 'greater' as such. The fact is that the electron affinity of F is smaller. This is because of F's small size and electron density. This makes it unfavourble to add another electron. Although it does become stable after it gains an electron, there is some repulsion that extra electron undergoes.

As far as same chemical properties of elements in same period is concerned : electronic configuration. I strongly suggest you look this up and learn what it actually is and how it works

[Evilservo]

Electron affinity depends upon the atomic radius of an atom the bigger the the radius  the lower the electron affinity the reason is
As we all know Nucleus is positively charged and electrons are negatively charged .. as the radius increases the outer most shell gets farther away from the nucleus thus the force of attraction between Nucleus and outermost electrons becomes less  a new coming electron will face more repulsion from electrons than attraction from Nucleus that is why u will see whenever you go down the period the electron affinity will decrease  .. that is obviously for those elements that accept electron not give in a chemical reaction
hope this helps as for your first question i don't know sorry