Bromide molecule -- bonding?

Question

I have to do some chemistry homework, and I'm stuck on one question:

"Describe, with diagrams, how the particles are held together in a molecule of bromide (Br2)"

I'm not sure if it's an ionic bond or a covalent bond.

Also, how many electrons are there in the outer shell? Is it 7? How do you work out how many electorons there are without looking at the periodic table. We got told that the 1st shell has 2 electorns, and that the rest each have 8. But that doesn't seem to be the case with the diagrams that I found on the net.

Answer 1

As this is Bromine bonded to bromine there is absolutely no difference between the electronegativity (ability to attract electrons) of the atoms bonded and so they both have an equal pull on each of the surrounding electrons making it purel covalent. ie as no atoms has a stronger pull than the other this does not create positive or negative charges.

The halogens end in 'ine' and as they are in group 7 this indicates that the atoms in this group have 7 outer electrons.

I have done a drawing of a diatomic molecule of Bromine and uploaded it here showing the outer electrons of the bromine atoms and the shared pair of electrons are shown in red using a diagram with sausage shaped orbitals

http://i28.photobucket.com/albums/c221/Scottie_Lass/BROMINE.jpg

Hope this helps =]

Answer 2

Bromine has 7 outershell electrons, so an atom will form a single bond with single atoms, a covalent bond, sharing the unpaired electron in each with each other.

Br - Br where - is a single covalent bond. The remaining 6 electrons per atom are located as 3 lone pairs.
-------------------------------------------------------------------------------------

Outer Shell electrons - maximum is only ever 8, except for H, He, Li, Be and B (they only have 1, 2, and 1, 2, 3 outershell electrons so can't shar enough to get to 8 in the outer shell). They are the special cases.

For all other shells, the MAXIMUM number of electrons in the OUTER shell is 8. Shells 3 and up can contain more than 8 electrons SO LONG AS THEY ARE NOT THE OUTER SHELL of that atom.

Maximum electrons per shell is 2n^2 where n = shell number

So 2, 8, 18, 32, 50 (so that takes care of the first 110 elements you would think; but no)

Shell 1 (K) has maximum of 2 electrons and the elements involved are the first row H and He:

Shell 2 (L) is the second row on the period table (8 members)

Shell 3 (M) is the third row on the period table (obvious 8 members - Na, Mg, Al, Si, P, S, Cl, Ar but that is still only 8 outershell

Shell 4 (N) is where the fun begins because:
K = 2,8,8,1 and Ca = 2,8,8,2 but then the First Row transition metal elements commence Sc, Ti.... with Sc = 2,8,9,2 Ti = 2,8,10,2 (check that I am correct on a detailed Periodic Table but the pattern is the case) V = 2,8,11,2; Cr = 2,8,13,1 just to be different; but you can see only 1 or 2 outershell electrons. By Zn = 2,8,18,2 the end of the first row of transition metals is reached, and the 3rd shell is full. Ga to Kr (including Br) then fills the 4th shell to got from 3 to 8 electrons in the outer shell as you move across the elements in that list.

The next row of the periodic table follows similar but more and more involved pattersn - 2,8,18,8,1 then 2,8,18,8,2 with the next element starting to fill the fourth shell increasing from 9 upwards; but the 5th shell only has 1 or 2 outer shell electrons for quite some distance across the 2 row of tansition metals (and those rare earth lantahnides come in to complicate the picture somehow as well

Good luck

Answer 3

It's a covalent bond. Bromine is an halogen like Fluoride (F_2) and chloride (Cl_2). Ionic bonding occurs when a metal (electropositive) bonds to a another element (electronegative) like an halogen, example NaCl = Na+ and Cl-.

The shells you are probably describing are the energy shells, 2 electrons maximum for the 1st shell, 8 electrons maximum for the 2nd shell, and so on to higher shells. The filling of these shells is, for low atomic number elements, in order, but for elements with higher atomic number is not!! It's more complicated. To work this out you can use Hund's rules (http://en.wikipedia.org/wiki/List_of_Hund's_rules). This is higher level because they involve angular momentum and spin, so diagrams can be confusing. But, believe in me, the 2nd shell of bromine has 7 electrons = 3 pairs + 1 lone. The lone electron forms covalent bond with the lone electron of the other element, Br2.

Answer 4

Lancenigo di Villorba (TV), Italy

Your question interests Bromine Molecule, e.g. Br2.
As I wrote, this is a Biatomic Molecule.

SKETCH
Here below, I draw it

........_....._
.......|Br--Br|
........_....._

Well, the atoms are similar as TWIN BROTHERs.

COVALENT OR IONIC?
Starting from this assumpt, the ELECTRON-VALENCE's SHARING BETWEEN TWIN ATOMs OBEY TO
EQUI-PARTITION.
In this fashion, I exclude any ionic nature for the Molecular Bond. Moreover, I exclude the Molecular Bond could be a Polar Covalent one bcause it is a PURE COVALENT BOND one.

OUTER SHELL
As I drawn, any Twin Atom show three electron duets in its outer shells, so any Twin Atoms have SEVEN ELECTRONs (e.g. 3 * 2 + Electron Valence) IN ITS OWN OUTER SHELL.

PERIODIC TABLE
Bromine is the Chemical Element having ATOMIC NUMBER as 35, e.g. Bromine lies in FOURTH PERIOD and SEVENTH GROUP.
It belongs to "p" Block, e.g. its Fundamental Electronic Configuration is

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5

where you see the ultimate Electrons as "p" TYPE.
Since it stands in 7th Group, it may expose 7 OUTERMOST ELECTRONs, as it does (e.g. 4s2 and 4p5 as 2 + 5 = 7).

I hope this helps you.

Answer 5

--..------ ..
:Br xo Br: (ignore the dashes... they keep electrons in place)
--''--------''
each dot is an electron. the x and o are bond electrons.

they both have seven in the outer shell, three lone pairs and one bond electron, they join their outer shells and those bond electrons orbit both atoms.
both atoms have the same electronegativity, so it is covalent and non polar.
oh and as for your shell configs
1st shell- 2 electrons
2- 8 electrons
3-8 electrons
4-18 electrons
5-18 electrons
6- 32 electrons
7- 32 electrons