@Saluja,
You're using the verb
appeared incorrectly, for starters.
Don't put quotation marks around the word
science - it's not a quote or a title or a statement of irony. It's
science. Quotation marks are not used for emphasis.
Don't pluralize the term
stuff. In fact, try not to use it much at all - you were gossiping and laughing, period. No need to add a few more padding words.
You say, "we tenth graders had
given our pre-boards". You're not giving the test (your teacher is); you're
taking the test, in idiomatically correct English.
Don't use the term
alright - it's incorrect. Yes, it's starting to appear as being acceptable, but you are trying to show off your education in this essay, yes? Then use the actual, correct term, which is a phrase:
all right.
You might want to go over your essay with a dictionary in front of you, and see the real meaning of a lot of the words that you're using, okay? It's salvageable, but a lot of the language is being used incorrectly, and that is going to be a big problem for you when you hand this in.