Why does oxygen have a double covalent bond

Oxygen almost always forms two bonds. In methionine, there are two types of oxygen atoms. One is bonded to two different atoms (a carbon and a hydrogen), the other forms two bonds to a single carbon atom.

Oxygen has 6 outer electrons. To complete a full octet, it needs two more. Because of this, it shares two of its own electrons and two electrons of another atom, giving it 6+2 (the shared ones from the other atom) = 8, a full octet.

Why is the oxygen always a double covalent bond

Oxygen has 6 outer electrons. To complete a full valence shell, it needs two more. Because of this, it shares two of its own electrons and two electrons of another atom, giving it 6+2 (the shared ones from the other atom) = 8, a full octet. This results in a happy oxygen.

To know how many bonds each element wants look on the periodic table. At the level of chemistry you're at now, you will draw bonds with only alkali metals, earth metals, other metals, and halogens.

Let's say we have Nitrogen. Nitrogen is group 15. Pretend the 1 is not there, only the 5. That five represents the amount of outer most electrons that nitrogen has. This is easily demonstrated in the Lewis Dot Diagrams. http://www.youtube.com/watch?v=ulyopnxjA...

If it has 5 and needs 8, it needs 3 more electrons so 3 bonds. With Fluorine it's in group 17, pretend the one is not there. Has 7, needs 8, so it will only bond with 1. With Catbon, it's in group 14. Needs 4, so four bonds. That's a little trick I like to use.

I hope that helped. Check out this video.. It's will 100% help you out!

1)Nitrogen
2)Both electrons come from Oxygen
3)Polar covalent(compare electronegativity)
4) hydrogen region
5) Not very sure, should be dispersion
6)Attraction between polar molecules
7)Breaking covalent bonds

PS Do your own homework

Which of the following is most likely to form multiple double or triple bonds

"Double" or "triple" bonds are covalent bonds that are made between two nonmetallic atoms. That leaves out Li. Both F and Cl have seven valence electrons, so they will most likely share only one valence electron with another atom to get one more electron completing the "octet". Therefore, they will most likely form single bonds with other atoms. Hydrogen has two options. It can lose one electron, like metals do, and become a positive ion, or it can share that one and only electron with another atom forming a "single" bond. (Of course, it can also gain one electron and become a negative ion like nonmetals do when reacting with a metal. That leaves N. Nitrogen atom has five valence electrons, and it needs three more to complete the octet. It will, therefore share three valence electrons of its own to get three more forming a triple covalent bond with another nitrogen atom.

What type of bond is generally formed between the halogens and the oxygen group

Nonpolar covalent bond.

Oxygen covalent bonding

The four orbitals that you are talking about are called 2s , 2px, 2py and 2pz orbitals.

The 6 valence electrons will occupy the orbitals in the following way.

The first two electrons will occupy the 2 s orbital first because it has a lower energy level.

The third electron will occupy the 2px orbital ( It can be any of the 2p orbital because all the three 2p orbitals are of the same energy level. They are said to be degenerate)

The fourth electron will occupy the 2py orbital.

The fifth electron will occupy the 2pz orbital.

The sixth electron will occupy 2px orbital.

So, we have two electrons in 2px, one each in 2py and 2pz.[ Again, it can be two in 2py, one each in 2px and 2pz ect..]

The reason that the electron try to be unpaired because since electron carries a negative charge, like charge repels each other. Unpaired electrons are more stable than paired electrons.
[ Hund's Rule]

So, one atom of oxygen has two unpaired electrons and they can be used to share with the lone electron of the other oxygen atom to form the covalent bond

Covalent Bonds and Examples

Covalent Bond is a bond formed by sharing of electrons. Usually they are formed by 2 non-metals. Say for example, Carbon and Oxygen they react together to form carbon dioxide. Also the elements located on the right side of the periodic table are non-metals except the inert gases (Helium, Neon and all those) and Hydrogen(which is a non-metal but located on the top-left side of the periodic table)
Examples:
Single covalent bond: Hydrogen and Chlorine which is HCl, then H2(hydrogen gas)

Double Covalent bond: Oxygen (O2)

Triple Covalent bond: Nitrogen (N2)

Hope I helped u.

Why is there 2 double bonds in so4 2 rather than just 4 single bonds

Good question!

Sulfur is an element that can show hypervalency (see "hypervalent molecule" in wikipedia for a detailed explaination), which is sometimes referred to as an expandable octet. This means that sulfur (and other hypervalent species) can support MORE than eight electrons in their outside orbital. Bear in mind that energetically, sulfur only WANTS to have 8 electrons in its valence shell, but it'll "allow" more if it reduces the overall unfavorable energy of the molecule. With that in mind, consider your SO4 2-. If there were only four single bonds, the molecule as a whole would carry a -4 charge (very unfavorable! very unstable! Oxygen will try to seduce some unsuspecting + charged atom/molecule to eliminate its negative charge!). The sulfur ends up "allowing" two more electrons into its outside shell, reducing the net charge on the whole molecule to -2.

Why does sulfur only allow two extra electrons instead of 4 to make a neutral molecule, I bet you're wondering. What actually happens is a little confusing, so stay with me. Each oxygen that's bonded to the sulfur is actually bonded with what you can think of as a one-and-a-half bond. That means that the -2 charge is distributed over ALL FOUR oxygens rather than just two (your chemical formula will probably say otherwise for clarity, but know that the one and a half bonds are more technically correct). This means that no one oxygen is THAT unhappy, so the molecule can carry a charge without as high risk of oxygen stealing someone else's + charged species (charged oxygen is a bully).

One last note: It's easy to think of atoms as a neat little nucleus ball with clearly defined rings of electrons orbiting around it. This idea works well for explaining bonding and energy level changes, but it's not quite accurate. In reality, an atom (element) is a glob of protons and neutrons surrounded by a cloud of electrons whizzing all about. Energy levels and orbitals describe region where you'll be most likely to find those electrons, but the electrons are always moving. If you can wrap your mind around that, it will help you understand the idea of partial bonds (those one and a half bonds we talked about) a little better.

Hope this makes sense! Ask away if you still have questions!