Question

the electronic configuration of Br is 2.8.18.7 what is its atomic number what is its valency​

Answer 1

Answer:

Explanation:

Atomic spectrum

A representation of the atomic spectrum of bromine.

Ionisation Energies and electron affinity

The electron affinity of bromine is 324.6 kJ mol‑1. The ionisation energies of bromine are given below.

Ionisation energies of bromine

Ionisation energy number Enthalpy / kJ mol‑1

1st 1139.86

2nd 2083.2

3rd 3364.5

4th 4610.3

5th 5750.0

6th 8431.9

7th 9941

8th 18580

9th 21610

10th 25180

11th 29040

12th 32610 (calculated)

13th 37920

14th 42070

15th 46410

16th 51140

17th 55670

18th 69110

19th 73430

20th 78130

21st 83940

Ionisation energies of bromine

Ionisation energies of bromine.

Effective Nuclear Charges

The following are "Clementi-Raimondi" effective nuclear charges, Zeff. Follow the hyperlinks for more details and for graphs in various formats.

Effective nuclear charges for bromine

1s 34.2471

2s 25.64 2p 31.06

3s 20.22 3p 19.57 3d 19.56

4s 10.55 4p 9.03 4d (no data) 4f (no data)

5s (no data) 5p (no data) 5d (no data)

6s (no data) 6p (no data)

7s

References

These effective nuclear charges, Zeff, are adapted from the following references:

E. Clementi and D.L.Raimondi, J. Chem. Phys. 1963, 38, 2686.

E. Clementi, D.L.Raimondi, and W.P. Reinhardt, J. Chem. Phys. 1967, 47, 1300.

Electron binding energies

Electron binding energies for bromine. All values of electron binding energies are given in eV. The binding energies are quoted relative to the vacuum level for rare gases and H2, N2, O2, F2, and Cl2 molecules; relative to the Fermi level for metals; and relative to the top of the valence band for semiconductors.

Label Orbital eV [literature reference]

K 1s 13474 [1]

L I 2s 1782 [2]

L II 2p1/2 1596 [2]

L III 2p3/2 1550 [2]

M I 3s 257 [2]

M II 3p1/2 189 [2]

M III 3p3/2 182 [2]

M IV 3d3/2 70 [2]

M V 3d5/2 69 [2]

Notes

I am grateful to Gwyn Williams (Jefferson Laboratory, Virginia, USA) who provided the electron binding energy data. The data are adapted from references 1-3. They are tabulated elsewhere on the WWW (reference 4) and in paper form (reference 5).

References

J. A. Bearden and A. F. Burr, "Reevaluation of X-Ray Atomic Energy Levels," Rev. Mod. Phys., 1967, 39, 125.

M. Cardona and L. Ley, Eds., Photoemission in Solids