a mixture of other elements including barium and krypton.

It was once thought that plutonium did not exist in nature, but trace amounts have been found in uranium ores.

The first production of plutonium was at the Oak Ridge National Laboratory in Tennessee. It was made for the Manhattan Project to make a nuclear bomb.

It was once used to power pacemaker batteries, but has since been replaced.WASHINGTON — Amid the chaos, Stephen Miller is in charge now.

The iconoclastic hard-line young conservative policy aide to President Donald Trump, hated by the left, and celebrated by the extreme right, is the obvious winner in the power struggle that led to Kirstjen Nielsen's ouster Sunday night as Homeland Security secretary.

Miller has unofficially taken the reins of border security amid a purge at the department that has also seen Secret Service Director Randolph "Tex" Alles removed from his job and Trump's pick to head the Immigration and Customs Enforcement agency, Ron Vitiello, yanked.

The Department of Homeland Security, a sprawling agency charged with defending the nation at home, does not have Senate-confirmed officials in the roles of secretary, deputy secretary, ICE chief, Secret Service director or inspector general. When