Atomic number:                  35     
    Standard atomic weight:          79.904 
    Symbol:                         Br     
    Group number:                    17     

bromine


General information

    Standard state:  liquid
    Colour:          brown, metallic lustre
    Discoveror:      Antoine J. Balard
    Date discovered: 1826
    Discovered at:   France
    Meaning of name: Gr. bromos, stench

Radii /pm

    Atomic:               114.5
    van der Waals:        185
    Covalent:             114
    Metallic:         

Valence shell orbital Rmax

    s:          77.2
    p:          89.1
    d:          22.9
    f:     

Ionic radii

    Ion       Coordination number and geometry
              4(tet)    4(sq pl)  6(oct,ls) 6(oct,hs) 8         Pauling
    M(-III)                                                               
    M(-II)                                                                
    M(-I)                                                                 
    M(I)                          166                 175       62        
    M(II)                                                                 
    M(III)                                                                
    M(IV)                         79                                      
    M(V)                          78                            70        
    M(VI)                                                                 
    M(VII)                                                                
    M(VIII)                                                               


Electronegativities

    Pauling:                2.96
    Sanderson:              2.96
    Allred Rochow:          2.74


Effective nuclear charge

    Slater:                 7.6
    Clementi:               9.03
    Froese-Fischer:        10.89


Bond enthalpies /KJ per mol

Single bond enthalpies

    M-F           187
    M-Cl          216
    M-Br          190
    M-I           175
    M-M       

Diatomics bond enthalpies in MM and MX

    MM             X                X                X
    193.857        N   276          O   235.1        F   250.2     
                   P                S                Cl  218.8     
                   As               Se  297          Br  193.857   
                   Sb               Te               I   179.1     
                   Bi  267.4     


Temperatures /K

    melting:              265.9
    boiling:              331.9
    critical:             584
    Debye:            
    superconduction:  
    m.p. hydride:         184.65
    b.p. hydride:         206.15
    m.p. fluoride:        240.15

Enthalpies /kJ per mol

    fusion:                10.8
    vaporisation:          30.5
    atomisation:          111.9
    bond:                 193.857

Ionization enthalpies /kJ per mol

    1st                  1139.9
    2nd                  2100
    3rd                  3500
    4th                  4560
    5th                  5760
    6th                  8550
    7th                  9938
    8th                 18600


Isotopic abundances

In the below list, the first number is the nominal mass number, the second the percentage abundance of that isotope, and the third is the accurate mass for that isotope.

     77           0          76.921378 
     78           0                 
     79          50.69       78.918336 
     80           0                 
     81          49.31       80.916269 
     82           0          81.914802 


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