Question

give reasons for the following questions of a) ,F block elements are kept separately in periodic table b), atomic size decreases of across the period c), In the first hydrogen and Helium or not a place adjacent to each other​

Answer 1

Periodic Trend

The atomic radius of atoms generally decreases from left to right across a period. There are some small exceptions, such as the oxygen radius being slightly greater than the nitrogen radius. Within a period, protons are added to the nucleus as electrons are being added to the same principal energy level