answersLogoWhite

0

Bohr notation describes the grouping of electrons within the different periods by orbital shells of an atom. For example, Lead (Pb) is an element in the 6th period, 14th group and has an electron configuration of [Xe] 6s24f145d106p2. Based on electron groupings of those orbitals, lead would have an electron grouping by period of 2 electrons in 1s, 8 in 2s2p, 18 in 3s3p3d, 32 in 4s4p4d4f, 32 in 5s5p5d5f, and 4 in 6s6p for a notation of:

2-8-18-32-32-4

This notation is not based on electron orbital energy level, but instead by the number of electrons in each period. This is significantly different than the filling of electrons by energy level that would actually group and fill the electrons in ascending energy levels:

1s, 2s, 2p3s, 3p4s, *3d4p5s, *4d5p6s, *4f5d6p7s, *5f6d7p

Notice specifically that energy levels for the "d" and "f" orbitals are out of sequence within the orbital levels because of their higher energy states relative to their period level. If grouped this way, the notation would look more like:

2-2-8-8-18-18-26

This notation is very redundant within the first six energy levels and can be confusing when compared with the period levels because of the out-of-sequence orbitals for the 3d, 4d, 5d, 4f, and 5f periods.

Also it is counter-intuitive to the periodicity to the sub-atomic organization within the periods while Bohr notation follows it exactly:

- 2 elements in period 1, 2 electrons in 1st set notation

- 8 elements in period 2, 8 electrons in 2nd set notation

- 18 in period 3, 18 in 3rd notation

- 32 in period 4, 32 in 4th notation

- 32 in period 5, 32 in 5th notation

- 46 in period 6, 46 in 6th notation

- 46 in period 7, 46 in 7th notation

(if you consider all "undiscovered" synthetics in the last two notations)

User Avatar

Wiki User

13y ago

What else can I help you with?