Please help I need to submit it today

-How to explain the decomposition reaction?

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

The kw for water at 0 °c is 0.12× 10–14 m2. calculate the ph of a neutral aqueous solution at 0 °c.