1) The teacher was struggling to teach the topic of the modern periodic table effectively through traditional methods and was not achieving the desired learning outcomes. 2) He developed a new approach where he assigned each student in the class the name of an element and had them physically arrange themselves according to the layout of the periodic table. 3) He also provided students with pages from old science notebooks that contained periodic tables and created WhatsApp groups to share additional review materials. This hands-on, active learning approach helped students better understand and remember the topic.