Can a child get chicken pox from touching a scab of a friend who has it?

Not usually. The scab is the final stage and is not contagious.The pox is when it is a blister.
Catching chicken pox. Not likely if all the pox sores have completely scabbed over, the child is no longer contageous. However if all the scabs are not completely scabbed over then the child is still contageous.

Related Questions

Can a child get chicken pox from touching the scabs of a playmate who has it?

Yes, indeed... ...Assuming the child doing the touching has not been vaccinated against chicken pox, he or she could certainly get it that way. Read more...
Not the scabs. Chicken pox is spread mostly by mucous droplets and contact ith the vessicles directly. But not the scabs. Read more...