Is this sentence correct?

There are a few grammar errors in this sentence. First, when I initially read the sentence, it seems to be missing a word. It sounds better to include the word “the” in between the words “to” and “students.” It is not wrong to exclude that word from the sentence, but it seems to flow better with the inclusion of that word.

Second, the sentence includes several different phrases that pertain to other parts of the sentence. If I wrote this sentence, I would have included the prepositional phrase “during the lecture” at the beginning of the sentence.

However, that is not mandatory. Finally, the last correction which would be mandatory would be to change the word “that.” Students are people so the word “who” should be used instead of “that.”