Can someone explain the caste system and how the Aryans come into play, and why some scholars believe they didn't exist? :) thanks

Historically, the caste system is believed to have begun with the arrival of the Aryans in India around 1500 BC. The Aryans contained the first mention and a background of the elements that make up the caste system. The Aryans came from southern Europe and northern Asia with fair skin that distinguished them from the native Indians.

Explanation:

because the two particles have an equal charge, the charges will cancel out and give the atom an overall charge of 0. so, if at atom has 35 protons in the nucleus, we could expect it to have 35 electrons orbiting that nucleus.