The interatomic distance is twice the value of rmetal, and so
the calculated value of the SnSn distance of 278pm is in
good agreement with the observed value of 280 pm.
Self-study exercises
Use data in Table 5.2.
1. Estimate a value for the metallic radius, rNa, in metallic Na
(298 K, 1 bar). [Ans. 185 pm]
2. The internuclear separation of two Na atoms in the metal
(298 K, 1 bar) is 372 pm. Estimate a value of rmetal appropriate
for 12-coordination. [Ans. 192 pm]