I am a chemistry teacher, I have been taking online classes for the last 10 years

Study from Nandlal sir and all your key concepts and doubts will be clear.
He is a fantastic teacher. He is a very patient and calm person.
Just you need to give him some time and stay connected with him.
Be consistent with his classes and everything will be perfect.
One more thing he is humorous too but it is not easy to understand his humour.

When Nand Lal sir says he will do something—whether it's checking a notebook, helping after class, or preparing students for exams—he follows through. This reliability makes students trust him.

His dedication to our success and well-being is evident in everything he does. Thank you for being a teacher we can always rely on."