That can't be. The universe is not infinite, therefore nothing in it is. If it were infinite it would not be expanding.
Of course everything is infinite. You can not create nor destory energy, so that means its infinite.
The universe is expanding, true, but at some point it will contract again to be one again, destroying life but soon after BIG BANG again and life will spring, what ends begins at the same time. Its a never ending cycle.
THe whole universe is 98% of space, nothingness, and so are atoms. No matter how you look at it, what ends, something new will begin, remember, energy can not be created nor destroyed, it will just transfer from one thing to another.