The number of electronic shells contained in an atom with electron configuration 1S\(^2\)2S\(^2\)2P\(^6\)3S\(^2\)3P\(^6\)4S\(^2\) is
In the extraction of iron, the waste gas from the furnace is a mixture of
In a neutralization reaction involving HCI and NaOH using litmus as indicator, the colour at the end point is
