magic mouse won't scroll on my MacBook air

Hello Bettyet,

Thanks for posting here in Apple Support Communities. There's a couple of things that you can try in attempts to resolve the issue you're facing. You can turn off the Magic Mouse by sliding off the power switch. You can also connect the lightning cable for a moment to see if this helps. The following article can walk you through doing so: If you can't connect your Magic Keyboard, Magic Mouse, or Magic Trackpad to your Mac - Apple Support

Cheers.