Which of the following has a noble gas electronic configuration?

Question

a. CL
b. O-
c.Br-
d.Cl+

Can someone please explain electronic configurations in laymen's terms (if possible?) I'm clueless!

Answer 1

The correct answer is Br-, the bromide ion. It has 35 protons
in the nucleus (or it wouldn't be bromine) but it has the extra
electron giving it a full outer shell, with 36 electrons, the same
as Krypton which is a noble gas. Since it has one more
electron than it has protons, it has a net charge of -1.
The electron configuration is just the way the electrons in an
atom are arranged in the various quantized shells, or orbitals
or energy levels or whatever you want to call them, around
the nucleus.
Hope this helps.

Answer 2

Bromine (Br) has aan Atomic mass of 80 and has 35 Protons and 45 Neutrons. It also has 35 Electrons in 4 Energy Shells as follows.
Shell 1...'K' Shell = 2
Shell 2 ...'L' Shell = 8
Shell 3 ...'M' Shell = 18
Shell 4 ...'N' Shell = 7

When Br is ionised by gaining an electron, Shell No. 4 will become 8 Electrons and give Br- ion.
The Noble Gas Krypton (Kr) has the above Electron Configuration but has 8 electrons in its outer shell.
2,8,18,8...Answer...'c'.

Answer 3

The answer is c. If you look at the periodic chart, bromine is in the VII or "halogen" family. It has 7 electrons in its outer valance shell, which configure as 2s2 2px2 2py2 1pz2. A noble gas configuration would be 2s2 2px2 2py2 2pz2. When bromine becomes a Br- ion, the extra electron completes the pz subshell.

Answer 4

look at the periodic table. notice that Br is right next to the rightmost column (the noble gases). That means that it has one less electron than the noble gas that comes right after it. Since the Br that we are talking about is Br MINUS (Br-) that means the Br has ONE MORE electron than usual. this gives it the same electron configuration as the noble gas immediately following it on the periodic table.

Answer 5

it's Br-