What element that is stable and have 3 energy levels

Wich technology can a website use to allow you to listen to a concert live over the internet?

When running anti-virus software , what could be a reason where recipitent is not guaranteed that data being streamed will not get interrupted?

Linux is distributed under gnu gpl. why is this important? a. it ensures that only torvalds can profit from the sale of linux b. it prevents unknowledgeable users from downloading programs they don't know how to operate. c. it provides protection for the developers who created linux. d. it states that anyone can copy, modify, and share the program if changes are made public.