My mom wants to send me abroad for a year, and i am going to refuse.
Why would you refuse that sort of opportunity?
I don't want to be separated from my friends
While this seems like an amazing experience that you might really enjoy, I understand not wanting to be away from friends for that long. If you are really that adamant about not going, your mom should respect your wishes.
I told her that I don't have to go anywhere since I have better opportunities here.
That's great, give her a real reason why staying is better and she will come around.