Atom Bonding Question?

Question

I do not understand chemistry and I want to know the difference in lone pairs and bonds and how each repel other atoms. Such as if water's two lone pairs were changed into bonds, what would the geometric shape be?
Placing atoms in places also confuses me, like does it matter where the Cl atoms are put in the dichloromethane (CH2Cl2) in the geometric or lewis structure (if the Cl's could be opposite or adjacent to each other). And since it is already filling it's all 8 electron shells, is the CH2Cl2 already non-polar? Or is it still polar?

Oh, and water has two lone pairs. The octet rule states that an atom needs 8 valence electrons. If O is bonded to 2 hydrogens, then it would have filled up 4 of the electron spaces. Now it needs 2 more pairs, so it will have 4 more electrons w/o bonds. These 4 electrons are lone pairs, resulting in 2 lone pair electrons.

Answer 1

The gentleman who answered above me is incorrect, and you are right. Water does have two lone pairs.

Now to try and answer your question.

The difference between lone pairs and bonds is obviously that lone pairs are not involved in a bond (think of it as a bridge) with another molecule. Also, it is usually the case that a bond (which contains two electrons) is composed of one electron from one molecule and another electron from the other molecule, though that is not always the case.

Whether or not the electron pair is in a bond or serving as a lone pair, it should not affect the electron configuration. Taking your water example, bonds and lone pairs reject each other equally, so the molecule adopts what is called a tetrahedral formation, since it has four components coming off the Oxygen (2 bonds and 2 lone pairs)

If you don't know what a tetrahedral conformation is, think of a four sided pyramid with the oxygen in the middle and each electron component (bond or lone pair) pointing toward a corner. It would not matter which component is pointing to which corner, because they would all be about 109 degrees apart.

Now if one of those lone pairs on the oxygen in your water example formed a double bond with one of the hydrogens (which breaks many rules of chemistry, but it's just an example) now you would have 3 components coming off the oxygen (1 single bond, 1 double bond, 1 electron pair) and they would adopt a trigonal planar (2-D triangle) conformation around the oxygen and would each be 120 degrees apart.

So in your CH2Cl2, you have a central Carbon with four bonds coming off it. One to each Hydrogen and one to eadch Chlorine. Since that makes four components, the Hydrogens and Chlorines will again adopt a tetrahedral conformation around the Carbon. Each bond will repel the others equally and the angular difference will be around 109.5 degrees. It does not matter where the chlorines or hydrogens are since they will be an equal distance apart in any configuration.

It's hard to think of this concept in three dimensions while you have to draw it in two dimensions, but it gets pretty easy with practice.

Answer 2

Water actually has one lone pair:
..
O
/ \
H H
This creates a negative charge on the side with the pair. The H tries to stay away from this charge. If the pair was a bond, then the molecule would still be polar due to the different electronegativities, but less so due to the fact that the electrons would be confined to a bond.

Answer 3

atoms bond with different atoms by potential of a phenomenon stated as chemical bonding A chemical bond is an charm between atoms or molecules and enables the formation of chemical components, which comprise 2 or extra atoms. A chemical bond is the charm led to by potential of the electromagnetic rigidity between opposing expenditures, the two between electrons and nuclei, or through fact the end results of a dipole charm. The power of bonds varies appreciably; there are "reliable bonds" including covalent or ionic bonds and "vulnerable bonds" including dipole-dipole interactions, the London dispersion rigidity and hydrogen bonding. considering opposite expenditures charm to by potential of an person-friendly electromagnetic rigidity, the negatively-charged electrons orbiting the nucleus and the certainly-charged protons interior the nucleus charm to one yet another. additionally, an electron located between 2 nuclei would be interested in the two one among them. subsequently, the main good configuration of nuclei and electrons is one wherein the electrons spend extra time between nuclei, than everywhere else in area. those electrons reason the nuclei to be interested in one yet another, and this charm outcomes interior the bond. regardless of the undeniable fact that, this assembly can't fall down to a length dictated by potential of the volumes of those individual debris. through issue wave nature of electrons and their smaller mass, they occupy a very plenty extra suitable quantity of quantity in comparison with the nuclei, and this quantity occupied by potential of the electrons keeps the atomic nuclei fairly far aside, whilst in comparison with the size of the nuclei themselves. ordinarily, reliable chemical bonding is linked with the sharing or pass of electrons between the engaging atoms. Molecules, crystals, and diatomic gases— certainly lots of the actual ecosystem around us— are held collectively by potential of chemical bonds, which dictate the form of remember.