Hydrogen (1H1), Deuterium (1H2), singly ionised Helium (2He4) and doubly ionised lithium (3Li6)++ all have one electron around the nucleus. Consider an electron transition from n = 2 to n = 1. Deuterium (1H2) Hydrogen (1H1) singly ionised Helium (2He4) and doubly ionised lithium (3Li6)++ all have one electron around the nucleus. Consider an electron transition from n = 2 to n = 1. October 20, 2020 Category: Uncategorised (JEE Advanced Physics by BM Sharma + GMP Solutions) , Facebook Messenger WhatsApp Share this:TwitterFacebook Related