43Tc[98]
Technetium
Transition metalsHard, shiny metals that conduct heat and electricity well and often form coloured compounds.
[Kr] 4d⁵ 5s²
- Atomic number
- 43
- Atomic mass
- [98]
- Protons
- 43
- Neutrons
- 55
- Electrons
- 43
- Shells
- 2, 8, 18, 13, 2
- State at 25 °C
- Solid
- Position
- Group 7, period 5
Proton (+)Neutron (0)Electron (−)
Discovered byCarlo Perrier and Emilio Segrè, 1937Emilio Segrè: 2 elements
It was the first element made artificially. The name comes from the Greek technetos, meaning artificial.
Did you know?
- It is the lightest element with no stable isotopes.
- Some stars show technetium in their light, proof they make elements.
Where it's found
- Made in nuclear reactors
- Tiny traces in uranium ores
What it's used for
- Technetium-99m for hospital scans, used in tens of millions of scans each year
Try it
There's no safe home experiment for Technetium. Explore it with the animated atom above instead.