Please help. I need this asap 30 points please

What volume of a 0.25 m solution can be made using 0.55 moles of ca(oh)2

The negative impacts of nonnative species generally outweigh the positive impacts

Which of the following types of stars is most likely to end up as a supernova? in graph a, the curve peaks at 800 nm, in the red section of the visible light spectrum. in graph b, the curve peaks at 550 nm, in the green section of the visible light spectrum. in graph c, the curve peaks at 450 nm, in the blue section of the visible light spectrum. in graph d, the curve peaks at 300 nm, in the violet section of the visible light spectrum. a b c d