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The bare copper wire is likely to be the ground wire.
Can you tell me the NEMA type written on the new plug and new socket that you have purchased, for example: 10-50R
Let me know so that we can continue.
I don't have that in front of me - I can attempt to get it from my email, but I hope I don't lose you meanwhile - but maybe this helps meanwhile - the new plug is what Sears delivery team will be bringing to connect - the salesman indicated a three wire outlet was needed - when I disconnected the existing range, which was hard wired, that's when I got confused and decided to find an answer. I'll wait to hear from you before I attempt to find the sales slips in my email file.
Ok, your black and white wires are your 240V. The terminals on the receptacle are likely labeled L1 and L2. It doesn't really matter how you hook these up.
The bare wire is your ground and connects to the G terminal on the receptacle.
That should do it.
Please let me know if you need more help with this.