All the students in my Science Olympiad class were jumping out of their seats, ecstatically waving their hands in the air and shouting "Pick me, pick me!" .
Sounds better, emphasizes eagerness, ya know?
With the help of Quantums, I celebrated both the students' successes and their mistakes. And with a strong emphasis on doing practice problems and homework, the phrase "practice makes prefect" nearly became our motto.
Unnecessary, really. The important thing is the celebration of successes/mistakes. To emphasize that, a standalone sentence is more powerful. Plus, Quantums are only mentioned very briefly while you list things earlier in the essay.
I strived to provide my students with the confidence and the courage to tackle any challenge.
sounds less stiff than "endeavoured"
It was also one of my hardest classes, and in that respect, I identify with my students
Be more direct, less passive. Instead of using "can" just state what you would say.
I broke down tough problems into more manageable steps.
Sounds... more manageable!
Also, you might want to clarify the age of the children. I think the picture that you paint with your essay is very good with the exception of this detail. I assume the children are middle schoolers but then, I'm not sure.
Overall:
1. Your structure might be helped by transferring the first paragraph into present tense. So first and last could be a "as of now" type of thing. I'm not sure how you want to write it all, but I think this could strengthen the essay.
2. I love Physics too! Great concept. It shows off how much you care for the subject and how much you care for your students. Your passion shines through the words.
Also, thank you for reviewing my essay! I appreciate the encouragement.