If the Sun could suddenly collapse to a black hole, how would the period of Earth's revolution about it differ from what it is now?

The period of Earth's revolution wouldn't change at all, but certainly we would die because of the cold and lightless space.

Explanation:

A black hole is a lot of matter in a really tiny space, even you could be a black hole, but your matter has to be compressed more than a thousand million two thousand million times a grain of salt and even if that happens I can get close to you as in a normal conversation and I wouldn't fall in the black hole and all of this because your gravitational force wouldn't have change.

So the mass of the sun would remain the same, doing the same gravitational force and keeping the earth on its normal course.