Mood is the feeling or atmosphere the writer creates for the reader? true or false

Hello! 

The answer to this question is True!
Mood is a literary element that is used to influence feelings for a reader. For example, the writer can create a sad mood to give the reader a broader understanding of a character's unhappy emotions. It is used so that the reader can relate more personally to the story and its characters. 

I hope this helps you! Have a great day!

True, the atmosphere creates a mood.
for example
"the starlight night across a smoky terrace" gives you a nice, night-like feeling, or mood