Mendelevium is a man made chemical element.
Mendelevium is an artificial, man made chemical element.
Mendelevium can be found only in rare specialized laboratories.
Many isotopes have 148 neutrons; example: mendelevium -249.
Yes, mendelevium is man made and radioactive.
It is a natural element.
Mendelevium.
Selenium is a natural element.
No it is not.
Lanthanum is a natural element.
Actinium is a natural chemical element, it is not a man-made element.
Argon is a natural element found in the air.
No, Uranium is naturally occurring. But all elements beyond uranium are man-made.