Answer:
Brackett Series (n = 4)
Explanation:
The least energetic line of Hydrogen atom lies in <em>Brackett Series </em>when n = 4 because these are least energetic, have longer wavelengths and lies in Infrared region of spectrum. No traces of <em>Pfund series </em>are formed by H=atoms.
Answer:
The heat would flow from the hot solid to the cool solid until all temperatures are near equal.
As the gas cools it condenses and becomes a liquid its atoms also become smaller