Why nylon discolour?

Where is the moho barrier located in the layers of earth? What are the geologic features found at transform plate boundaries? What effect has titania and oberons quarrel had on nature on the seasons on the humans? How many amps does 800 joules equal? What is 9f 16g-15f-30g? What produced the helium now present in the sun's core? What can be recyled? How many fingers does the average person have? What money do they have in Africa? Why must cooked food be kept hot or cold but never at room temperature? What happens to the molecules in dry ice as it undergoes a phase change from solid to gas? How this adaptation helps control water loss? Where did the carbon dioxide and water vapour come from 4.5 billion years ago? Cocoa Beach water temp in April? Characteristics of dwarf planet? What does the inside of a monocot seed look like? Why is selective breeding bad? Is barium magnetic? What are the 3 stages of reintegration? What are the different layers of the earth structure?