Rubidium: bond enthalpies in gaseous diatomic species

The bond energy in the gaseous diatomic species RbRb is 48.898 ±0.005 kJ mol-1.

The following values refer to neutral heterodiatomic molecules in the gas phase. These numbers may well differ considerably from, say, single bond energies in a solid. All values are given in kJ mol-1.

Table of diatomic RbX bond enthalpies. All values are quoted in kJ mol-1. Each formula in the table (RbO, RbF, and so on) is a link - select these to see visual periodicity representations for bond enthalpies involving rubidium to elements of your choice.

Period 1

RbH             RbHe
167 ±21              

Period 2

RbLi RbBe RbB RbC RbN RbO RbF RbNe
          255 ±84 494 ±21  

Period 3

RbNa RbMg RbAl RbSi RbP RbS RbCl RbAr
63.25           427.6 ±8  

Period 4

RbK RbCa RbGa RbGe RbAs RbSe RbBr RbKr
            380.7 ±4  

Period 5

RbRb RbSr RbIn RbSn RbSb RbTe RbI RbXe
48.898 ±0.005           318.8 ±2.1  

Period 6

RbCs RbBa RbTl RbPb RbBi RbPo RbAt RbRn
49.57 ±0.01              

Period 7

RbFr RbRa            


I am grateful to Professor J.A. Kerr (University of Birmingham, UK) for the provision of the bond strengths of diatomic molecules data.

The values given here are at 298 K. All values are quoted in kJ mol-1. Generally, these data were obtained by spectroscopic or mass spectrometric means. You should consult reference 1 for further details. A note of caution: the strength of, say, the C-H bond in the gaseous diatomic species CH (not an isolable species) is not necessarily, the same as the strength of a C-H bond in, say, methane.

The strongest bond for a diatomic species is that of carbon monoxide, CO (1076.5 ± 0.4 kJ mol-1). The strongest bond for a homonuclear diatomic species is that of dinitrogen, N2 (945.33 ± 0.59 kJ mol-1).


  1. J.A. Kerr in CRC Handbook of Chemistry and Physics 1999-2000 : A Ready-Reference Book of Chemical and Physical Data (CRC Handbook of Chemistry and Physics, D.R. Lide, (ed.), CRC Press, Boca Raton, Florida, USA, 81st edition, 2000.

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rubidium atomic number