script

Dear native English teachers

This is my script for a speech in my class.
Could you please correct errors or strange expressions to native speakers?

1.
I'm going to be talking about the scientist Lewis.
He was an American chemist and a professor at UCB, who majorly studied physical chemistry.
What is physical chemistry?
It is “the branch of chemistry concerned with the application of the techniques and theories of physics to the study of chemical systems”.
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2.
What did he achieved?
He is known for the discovery of the covalent bond, which means a chemical bond that involves the sharing of electron pairs between atoms.
Let's watch a video clip showing how one oxygen atom and two hydrogen atoms are covalently bonded to form a water molecule. (...)
In addition, he suggested an even more general definition of acid and base than that of other scientists.
A Lewis acid is an electron-pair acceptor, and a Lewis base is an electron-pair donor.
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3. What is his current-day influence? He was the first to produce a pure sample of heavy water, or water in which hydrogen is replaced by deuterium. Deuterium is heavier than normal hydrogen, hence the name heavy water. Heavy water is an important compound because it is often used when producing nuclear energy.
And his contribution to chemistry is an important factor that built UCB's chemistry department into today world's best.
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4. Lewis never won the Nobel Prize. When staying abroad in Germany, he studied under the chemist Nernst. While working in Nernst's lab, Nernst and Lewis apparently developed a lifelong enmity. A friend of Nernst's happened to be a member of the Nobel Chemistry Committee. It is claimed that there is evidence that he used the Nobel nominating and reporting procedures to block a Nobel Prize for Lewis.