Answers

  • Brainly User
2014-04-20T21:59:20+05:30
Isoelectonic are those which have same no of electrons 
H- = 2 electrons
He = 2 electrons 

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2014-04-21T12:15:13+05:30
I think you mean hydride ion....

hydride ion have two electron which is equal to he ion and thus they are isoelectronic.
I hope this is sufficient.
Hydride ion is H- ion  
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