Is it normal for teens to be rude to adults?

anything rude is not normal. most teens today are very disrespectful

It is usual for teens swear, be moody, be naive and/or be rude; that should answer your question, unless you didn't ask the question you actually wanted to ask.

Uh literally everyone is rude to everyone 

No it's not normal and shows very bad parenting.

Well, not sure about normal, but I would say they're more likely than most age groups to be rude to them.  It definitely is common for them to be rude/disrespectful to their parents. And for some teens, to adults other than just parents. But there are plenty of teens who know it's not right behavior and won't be rude to other adults.

YES! Teens are going through a tough time! Sometimes yo uhave to accept that they are not your little kids anymore and give them some more freedom. When they are rude, don't give them the power over you. Stay assertive and calm.

Usually teens bully kids their same age

No. But it is common for the ungraceful and ignorant little sh*ts to be rude punks.