Which of the following would result in a chemical change

One day, after pulling down your window shade, you notice that sunlight is passing through a pinhole in the shade and making a small patch of light on the far wall. you see that the patch of light seems to be a circular diffraction pattern. it appears that the central maximum is about 1 cm across and you estimate that the distance from the window shade to the wall is about 3 m. what is (a) the average wavelength of sunlight? (b) the diameter of the pinhole?

Which pair of quantities includes one quantity that increases as the other decreases during simple harmonic motion?

Aviolently rotating column of air is formed around a region of extremely low air pressure above land. which of these weather conditions is most likely to follow? blizzard cyclone tornado hurricane