Mary lay in bed and watched the constellations move on the ceiling over her head. her parents had brought her a star projector that projected them there. the stars moved in a circle across the ceiling, so her view was always changing. is this what happens in real life?

a) yes the stars orbit the sun
b)yes the stars are orbiting around the earth
c)no both the earth and stars are orbiting around the sun
d) no the earth moves, which makes the stars appear to move

The graph below compares the rates of reaction of a burning candle and an exploding firework. comparing chemical reactions what can you conclude from the graph? the reaction that causes a firework to explode requires less energy to start, and occurs more rapidly than the reaction that causes a candle to burn. the reaction that causes a firework to explode requires less energy to start, and occurs less rapidly than the reaction that causes a candle to burn. the reaction that causes a firework to explode requires more energy to start, and occurs less rapidly than the reaction that causes a candle to burn. the reaction that causes a firework to explode requires more energy to start, and occurs more rapidly than the reaction that causes a candle to burn. mark this and return