It is an extremely radioactive synthetic element (an element that can be created in a laboratory but is not found in nature); the most stable known isotope, meitnerium-278, has a half-life of 7.6 seconds.
It is an extremely radioactive synthetic element (an element). This element can be created in a laboratory. This element is not found in nature. The most stable known isotope has a half-life of 7.6 seconds. The most stable known isotope is meitnerium-278.