If my final exam is worth 30% and my class average is 80, what do i need to get to pass the exam?

Idon’t quite understand this problem

What is a subatomic particle with a negative charge and very little mass?

In this thread, i would like you to comment on the nature of light and how operation of telescopes. light has a duality of a particle and a wave; which one affects your life? also how does light interact with optics inside telescopic systems? answer these questions in two paragraphs. then respond the another students response.