Technetium

43
Tc
Group
7
Period
5
Block
d
Protons
Electrons
Neutrons
43
43
55
General Properties
Atomic Number
43
Atomic Weight
[98]
Mass Number
98
Category
Transition metals
Color
Silver
Radioactive
Yes
From the Greek word technetos, artificial
Crystal Structure
Simple Hexagonal
History
Element 43 was predicted on the basis of the periodic table, and was erroneously reported as having been discovered in 1925, at which time it was named masurium.

The element was actually discovered by Carlo Perrier and Emilio Segrè in 1937.

It was also found in a sample of molybdenum sent by Ernest Lawrence that was bombarded by deuterons in the Berkeley cyclotron.
Electrons per shell
2, 8, 18, 13, 2
Electron Configuration
[Kr] 4d5 5s2
Tc
Technetium was the first element to be produced artificially
Physical Properties
Phase
Solid
Density
11.5 g/cm3
Melting Point
2430.15 K | 2157 °C | 3914.6 °F
Boiling Point
4538.15 K | 4265 °C | 7709 °F
Heat of Fusion
23 kJ/mol
Heat of Vaporization
550 kJ/mol
Specific Heat Capacity
-
Abundance in Earth's crust
n/a
Abundance in Universe
n/a
Emilio
Image Credits: pauli.uni-muenster.de
Emilio Segrè, one of the discoverer of the element
CAS Number
7440-26-8
PubChem CID Number
n/a
Atomic Properties
Atomic Radius
136 pm
Covalent Radius
147 pm
Electronegativity
1.9 (Pauling scale)
Ionization Potential
7.28 eV
Atomic Volume
8.5 cm3/mol
Thermal Conductivity
0.506 W/cm·K
Oxidation States
-3, -1, 1, 2, 3, 4, 5, 6, 7
Applications
Technetium is used in nuclear medicine to carry out a number of medical tests, mainly relating to imaging and functional studies of internal bodily organs like bone scan.

It is also used industrially for equipment calibration following its approval as a standard beta emitter.

Mild carbon steels may be effectively protected by minute quantities of technetium, but this corrosion protection is limited to closed systems because of technetium's radioactivity.
Technetium is harmful due to its radioactivity
Isotopes
Stable Isotopes
-
Unstable Isotopes
85Tc, 86Tc, 87Tc, 88Tc, 89Tc, 90Tc, 91Tc, 92Tc, 93Tc, 94Tc, 95Tc, 96Tc, 97Tc, 98Tc, 99Tc, 100Tc, 101Tc, 102Tc, 103Tc, 104Tc, 105Tc, 106Tc, 107Tc, 108Tc, 109Tc, 110Tc, 111Tc, 112Tc, 113Tc, 114Tc, 115Tc, 116Tc, 117Tc, 118Tc