Look at the snake in the tall grass!
an explanatory sentence is explaining what you said in your topic sentence
I hope my answer causes a lot of excitement!
Answering your question gave me a feeling of excitement.
it is a noun. The excitement made me happy.
The room was abuzz with excitement as the Bride appeared at the top of the stairs.
Oh, dude, the nouns in that sentence are "excitement" and "air." Excitement is like, the feeling of being all pumped up, and air is like, you know, the stuff we breathe. So, yeah, those are the two nouns in that super thrilling sentence.
My excitement will diminish.
You could see the excitement of the four year olds as they played in the water.
All of these options would adequately clarify the meaning of the modifier.
Exclamatory
The little boy couldn’t contain his excitement as he watched the piñata smash open, spilling candy everywhere.
The girl jumped high into the air with excitement smeared across her face!