The half-life of radium is about 1600yr. Of 100 g of radium existing now, 25 g will remain unchanged after 25 g will remain unchanged after The half-life of radium is about 1600yr. Of 100 g of radium existing now August 16, 2020 Category: Chapter 31 - Nuclei , NEET Last 32 Years Solved 1988 - 2019 Physics and Chemistry Video Solutions , Physics , Facebook Messenger WhatsApp Share this:TwitterFacebook Related