Answer:
Technetium
Explanation:
The Mendeleev element called eka-manganese is now called Technetium.
Technetium is a crystalline, silver and radioactive metal, very similar to platinum. It serves as a gamma ray source of beta particles. Most of the technetium produced on Earth is a byproduct of uranium-235 fission in nuclear reactors and is extracted from nuclear fuel rods. No isotope of technetium has a half-life of more than 4.2 million years, so its detection in 1952 helped reinforce the theory that stars can produce heavier elements.
