See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

            4 2 4 2 Be 4 He 2 h m Be U m He 4 x h 9 y m Be m He U              y – x = 5 AITS-FT-XII-PCM(Sol.)-JEE(Main)/2021 FIITJEE Ltd., FIITJEE House, 29-A, Kalu Sarai, Sarvapriya Vihar, New Delhi -110016, Ph 46106000, 26569493, Fax 26513942 website: www.fiitjee.com 10