 11 contains a Xe – Xe bond , the longest element @-@ element bond known ( 308 @.@ 71 pm = 3 @.@ 0871 Å ) . 
 11 <a href='uninflect' title='1'><mark>contains</mark></a> a Xe – Xe bond , the longest element @-@ element bond known ( 308 @.@ 71 pm = 3 @.@ 0871 Å ) . 
11 contain a Xe – Xe bond , the longest element @-@ element bond known ( 308 @.@ 71 pm = 3 @.@ 0871 Å ) .