Teknisyo

Ang technetium ( /tɛkˈniːʃiəm/) ay isang kemikal na elemento na may simbolong Tc at atomikong bilang na 43. 

Technetium, ₄₃Tc

Technetium
Bigkas	/tɛkˈniːʃ(i)əm/ ​(tek-NEE-sh(ee-)əm)
Appearance	shiny gray metal
Bilang na pangmasa	[97] (data not decisive)[a]
Technetium sa talahanayang peryodiko
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Mn ↑ Tc ↓ Re molybdenum ← technetium → ruthenium
Atomikong bilang (Z)	43
Group	7
Period	5
Block	d-block
Electron configuration	[Kr] 4d5 5s2
Electrons per shell	2, 8, 18, 13, 2
Physical properties
Phase at STP	solido
Melting point	2430 K ​(2157 °C, ​3915 °F)
Boiling point	4538 K ​(4265 °C, ​7709 °F)
Density (at 20° C)	98Tc: 11.359 g/cm3 99Tc: 11.475 g/cm3[2]
Heat of fusion	33.29 kJ/mol
Heat of vaporization	585.2 kJ/mol
Molar heat capacity	24.27 J/(mol·K)
Vapor pressure (extrapolated) P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2727 2998 3324 3726 4234 4894
Atomic properties
Oxidation states	−3, −1, 0, +1,[3] +2, +3,[3] +4, +5, +6, +7 (isang matapang na asidikong oksido)
Electronegativity	Pauling scale: 1.9
Ionization energies	1st: 686.9[4] kJ/mol 2nd: 1470 kJ/mol 3rd: 2850 kJ/mol
Atomic radius	empirical: 136 pm
Covalent radius	147±7 pm
Van der Waals radius	205 pm
Mga linyang espektral ng technetium
Other properties
Crystal structure	​hexagonal close-packed (hcp) (hP2)
Lattice constants	a = 274.12 pm c = 439.90 pm (at 20 °C)[2]
Thermal expansion	8.175×10−6/K (at 20 °C)[2]
Thermal conductivity	50.6 W/(m⋅K)
Electrical resistivity	200 nΩ⋅m (at 20 °C)
Magnetic ordering	Paramagnetic
Molar magnetic susceptibility	+270.0×10−6 cm3/mol (298 K)[5]
Speed of sound thin rod	16,200 m/s (at 20 °C)
CAS Number	7440-26-8
History
Prediction	Dmitri Mendeleev (1871)
Discovery and first isolation	Emilio Segrè and Carlo Perrier (1937)
Isotopes of technetium t b
Main isotopes[1] Decay abun­dance half-life (t1/2) mode pro­duct 95mTc synth 61.96 d β+ 95Mo IT 95Tc 96Tc synth 4.28 d β+ 96Mo γ – 97Tc synth 4.21×106 y ε 97Mo 97mTc synth 91.1 d IT 97Tc ε ... 98Tc synth 4.2×106 y β− 98Ru β+ – 99Tc trace 2.111×105 y β− 99Ru 99mTc synth 6.01 h IT 99Tc β− –
Kategorya: Technetium tingnan usapan baguhin | references

Talababa

1. The most stable isotope of technetium cannot be determined based on existing data due to overlapping measurement uncertainties for the half-lives of the two longest-lived isotopes. The half-life of ⁹⁷Tc with an uncertainty corresponding to one standard deviation is 4.21±0.16 million years, while that for ⁹⁸Tc is 4.2±0.3 million years; these measurements have overlapping confidence intervals.^[1]