Shape of things to comeResearchers find three never-before-observed isotopes

Most people probably think that scientists had already cataloged the 118 natural elements — from hydrogen to silicon to uranium — and their various isotopes. In fact, only the first eight elements — hydrogen to oxygen — have had all their isotopes recorded. At Michigan State University’s National Superconducting Cyclotron Laboratory (NSCL) they wanted to change that, and Spartans researchers began smashing atoms in hopes of cataloging the isotopes for the other 110 elements on the periodic table. So far, they have found three never-before-observed isotopes of silicon, aluminum, and magnesium. “We are doing classical atom smashing — a beam of particles accelerated to half the speed of light is broken up against a target while a tandem mass spectrometer separates out all the different kinds of particles and identifies them,” said Dave Morrissey, a professor at the Lansing, Michigan-based University. “Our new isotopes only last a fraction of a second before undergoing radioactive decay, but by confirming their existence, we are helping other scientists design new materials and understand astronomical events, like supernovas.”

The three new isotopes discovered at the NSCL are silicon-44, aluminum-42, and magnesium-40. Silicon found in nature has only three stable isotopes: silicon-28 (92 percent in nature), silicon-29 (4 percent), and silicon-30 (4 percent). Magnesium also has three stable isotopes: magnesium-24 (79 percent), magnesium-25 (10 percent), and magnesium-26 (11 percent). Aluminum has only single stable isotope — aluminum-27 — but exists in radioactive isotopes ranging from aluminum-21 up to aluminum-43, the latter observed in a single glimpse for the first time at NSCL. By discovering all the isotopes for an element, design engineers can more accurately tailor future materials to an application’s needs.