1. when a star collapses to form a black hole, its mass
a. decreases
b. remains the same

B: The black hole does not give off mass, it only becomes smaller and denser. Hence why the gravity is so strong.

It does not have anymore fuel to burn and that is why it collapses. I think it is a. decreases

igneous rocks also form where plates converge. the subducting plate melts as it sinks into the crust of the earth, and the melt rises into the overriding plate forming volcanoes. metamorphic rocks are formed mainly in the lithosphere, wherever there is high pressure and high temperature. -woods