Theory of atomic-mass calculation  

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How can I calculate a significant atom-mass from the Atomic Number Order ?  
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  Z=(input): EGT = -2: ATM = 0  For H = 1 To 16         EGT = EGT + FNA(H)            If Z > EGT Then ATM = Int((2 + (0.0957911 *H)) * Z) - 1   Next H If Z = Int(Z / 3) * 3 Then If Z <= 18 Or (Z > 64 And Z < 98) Or (Z > 180 And Z < 242) Or (Z > 360 ) And Z < 450) Then ATM =  ATM + 1 Else ATM = ATM -1  Print "significant atomic mass = neutrons"; ATM - Z; " + protons " Z; " ="; ATM  
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Is the significant atom-mass equivalent with the relative atom-weight?

No, usually both values are near with each other. The relative atom-weight calculates itself from the  procentage of all isotopes of one element. The significante atom-mass is declared as completely-number (mostly in the middle of the isotopes). It gives a reference number with the known isotopes [Naturally Abundant] and with the unknown elements a trend to the likely possible and stable elements.

You can see such isotopes  at the isotopes table. Attention, very long loading time!  Isotopes.pdf The elements with significant atom-mass are marked as elements with blue or  red fields and white ink. [ see also: Moller Theoretical Nuclear Chat  Moller.pdf ]   
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significant/relativ atomic mass
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atomic mass of element 100 to 120
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Comparison of the deviation between significant atom-mass and relative atom-weight

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Top       Examples

Sn - 118     Tin

Sn 50
Z=50: EGT = -2: ATM = 0
For H = 1 To 16

 h = 1

 2 3 4 5
EGT = EGT + FNA(H)

 EGT = 0

 8 16 34 52
If Z > EGT Then ATM = Int((2 + (0.0957911 *H))  * Z) - 1

 ATM = 104

 109 113 118 Stop
Next H
If Z = Int(Z / 3) * 3  Then  .......                                         ( No )

Print "significant atomic mass = neutrons"; ATM - Z; " + protons " Z; " ="; ATM  ATM = 118;      neutrons = 68;     protons = 50
 

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Uuh - 297          Ununhexium

Uuh 116
  		Z=116: EGT = -2: ATM = 0
For H = 1 To 16

 h = 1

 2 3 4 5 6 7  
EGT = EGT + FNA(H)

 EGT = 0

 8 16 34 52 84 116
If Z > EGT Then ATM = Int((2 + (0.0957911 *H)) * Z) - 1

 ATM = 242

 253 264 275 287 298 Stop
Next H
If Z = Int(Z / 3) * 3 Then   .......                                       ( -1 )

Print "significant atomic mass = neutrons"; ATM - Z; " + protons " Z; " ="; ATM ATM = 297;   neutrons = 181;    protons = 116
 

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Ubs-338            Unbiseptium

Ubs 127
 

Z=127: EGT = -2: ATM = 0
For H = 1 To 16

 h = 1

 2 3 4 5 6 7 8
EGT = EGT + FNA(H)

 EGT = 0

 8 16 34 52 84 116 166
If Z > EGT Then ATM = Int((2 + (0.0957911 *H)) * Z) - 1

 ATM=265

 277 289 302 314 326 338 Stop
Next H
If Z = Int(Z / 3) * 3  Then    .......                                   ( No )
Print "significant atomic mass = neutrons"; ATM - Z; " + protons " Z; " ="; ATM ATM = 338  neutrons = 211    protons = 127
 

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The identity of an element is the number of protons in its nucleus. Since protons repel each other, neutrons must be present in the nucleus to hold the protons together. For example, carbon has 6 protons in its nucleus by definition. To hold these protons together, it takes at least 6 neutrons. However, carbon atoms may also have 7 or 8 neutrons. Since carbon comes in more than one variety due to differing numbers of neutrons, carbon is said to come in more than one "isotope". All atoms are "isotopes". But each element has its most common isotope. Since many isotopes are unstable (radioactive), some people think the word "isotope" implies radioactivity, but really it doesn't.

Generally, the more protons in the atom, the higher the proportion of neutrons needed to hold it together.  This proportion is described by the aforementioned formula.   

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Nuclear Masses: David Lunney; CSNSM     
 Experimental Programs, Theoretical Models and Astrophysical Interest.   Experimental Programs, Theoretical Models and Astrophysical Interest

The Berkeley site:  http://ie.lbl.gov/toimass.html

CAWIA

http://www.physics.curtin.edu.au/IUPAC/index.html

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Atomic weights of the elements. Review 2000 (IUPAC Technical Report),  by J. R. de Laeter, 
J. K. Böhlke, P. De Bièvre, H. Hidaka, H. S. Peiser,  K. J. R. Rosman, and P. D. P. Taylor 
Pure Appl. Chem. 75(6), pp. 683-799, 2003

http://www.iupac.org/publications/pac/2003/7506/7506x0683.html  IUPAC Technical Report

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isotopes

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APSIDIUM © Created:

2001-04-18

 

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2004-05-28