[填空题]
Calculate the bond lek ki.wdazhg n la 9-n.6q,zu/ 6z.sv6hngkx-( ecapab6 /ur3fo4th for the NaCl molecule given that three successive wavelengths for rotational transitions are 23.1 mm, 11.6 mm, and 7.7rpa f cx643(eau/kob -1 mm. $r = $ $\times 10^{-10}\ \text{m}$
