Pls help physics

What is the internal energy of 4.00 mol of diatomic nitrogen gas n2 at 455k

The frequency of the fundamental of the guitar string is 320 hz. at what speed v do waves move along that string?

One number is said to be an "order of magnitude" larger than another number if choose one: a. it is 10 times larger. b. it is 5 times larger. c. it is 3 times larger. d. it is 100 times larger. e. it is 2 times larger.