Krypton

  • krypton, 36kr
    krypton discharge tube.jpg
    a krypton-filled discharge tube glowing white
    krypton
    pronunciationn/ (krip-ton)
    appearancecolorless gas, exhibiting a whitish glow in an electric field
    standard atomic weight ar, std(kr)83.798(2)[1]
    krypton in the periodic table
    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
    ar

    kr

    xe
    brominekryptonrubidium
    atomic number (z)36
    groupgroup 18 (noble gases)
    periodperiod 4
    blockp-block
    element category  noble gas
    electron configuration[ar] 3d10 4s2 4p6
    electrons per shell2, 8, 18, 8
    physical properties
    phase at stpgas
    melting point115.78 k ​(−157.37 °c, ​−251.27 °f)
    boiling point119.93 k ​(−153.415 °c, ​−244.147 °f)
    density (at stp)3.749 g/l
    when liquid (at b.p.)2.413 g/cm3[2]
    triple point115.775 k, ​73.53 kpa[3][4]
    critical point209.48 k, 5.525 mpa[4]
    heat of fusion1.64 kj/mol
    heat of vaporization9.08 kj/mol
    molar heat capacity20.95[5] j/(mol·k)
    vapor pressure
    p (pa) 1 10 100 1 k 10 k 100 k
    at t (k) 59 65 74 84 99 120
    atomic properties
    oxidation states0, +1, +2 (rarely more than 0; oxide is unknown)
    electronegativitypauling scale: 3.00
    ionization energies
    • 1st: 1350.8 kj/mol
    • 2nd: 2350.4 kj/mol
    • 3rd: 3565 kj/mol
    covalent radius116±4 pm
    van der waals radius202 pm
    color lines in a spectral range
    spectral lines of krypton
    other properties
    natural occurrenceprimordial
    crystal structureface-centered cubic (fcc)
    face-centered cubic crystal structure for krypton
    speed of sound(gas, 23 °c) 220 m·s−1
    (liquid) 1120 m/s
    thermal conductivity9.43×10−3  w/(m·k)
    magnetic orderingdiamagnetic[6]
    magnetic susceptibility−28.8·10−6 cm3/mol (298 k)[7]
    cas number7439-90-9
    history
    discovery and first isolationwilliam ramsay and morris travers (1898)
    main isotopes of krypton
    iso­tope abun­dance half-life (t1/2) decay mode pro­duct
    78kr 0.36% 9.2×1021 y[8] εε 78se
    79kr syn 35 h ε 79br
    β+ 79br
    γ
    80kr 2.29% stable
    81kr trace 2.3×105 y ε 81br
    γ
    82kr 11.59% stable
    83kr 11.50% stable
    84kr 56.99% stable
    85kr syn 11 y β 85rb
    86kr 17.28% stable
    category category: krypton
    | references

    krypton (from ancient greek: κρυπτός, romanizedkryptos "the hidden one") is a chemical element with the symbol kr and atomic number 36. it is a colorless, odorless, tasteless noble gas that occurs in trace amounts in the atmosphere and is often used with other rare gases in fluorescent lamps. with rare exceptions, krypton is chemically inert.

    krypton, like the other noble gases, is used in lighting and photography. krypton light has many spectral lines, and krypton plasma is useful in bright, high-powered gas lasers (krypton ion and excimer lasers), each of which resonates and amplifies a single spectral line. krypton fluoride also makes a useful laser medium. from 1960 to 1983, the official length of a meter was defined by the 606-nanometer wavelength of the orange spectral line of krypton-86, because of the high power and relative ease of operation of krypton discharge tubes.

  • history
  • characteristics
  • applications
  • precautions
  • see also
  • references
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Krypton, 36Kr
Krypton discharge tube.jpg
A krypton-filled discharge tube glowing white
Krypton
Pronunciationn/ (KRIP-ton)
Appearancecolorless gas, exhibiting a whitish glow in an electric field
Standard atomic weight Ar, std(Kr)83.798(2)[1]
Krypton in the periodic table
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
Ar

Kr

Xe
brominekryptonrubidium
Atomic number (Z)36
Groupgroup 18 (noble gases)
Periodperiod 4
Blockp-block
Element category  Noble gas
Electron configuration[Ar] 3d10 4s2 4p6
Electrons per shell2, 8, 18, 8
Physical properties
Phase at STPgas
Melting point115.78 K ​(−157.37 °C, ​−251.27 °F)
Boiling point119.93 K ​(−153.415 °C, ​−244.147 °F)
Density (at STP)3.749 g/L
when liquid (at b.p.)2.413 g/cm3[2]
Triple point115.775 K, ​73.53 kPa[3][4]
Critical point209.48 K, 5.525 MPa[4]
Heat of fusion1.64 kJ/mol
Heat of vaporization9.08 kJ/mol
Molar heat capacity20.95[5] J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 59 65 74 84 99 120
Atomic properties
Oxidation states0, +1, +2 (rarely more than 0; oxide is unknown)
ElectronegativityPauling scale: 3.00
Ionization energies
  • 1st: 1350.8 kJ/mol
  • 2nd: 2350.4 kJ/mol
  • 3rd: 3565 kJ/mol
Covalent radius116±4 pm
Van der Waals radius202 pm
Color lines in a spectral range
Spectral lines of krypton
Other properties
Natural occurrenceprimordial
Crystal structureface-centered cubic (fcc)
Face-centered cubic crystal structure for krypton
Speed of sound(gas, 23 °C) 220 m·s−1
(liquid) 1120 m/s
Thermal conductivity9.43×10−3  W/(m·K)
Magnetic orderingdiamagnetic[6]
Magnetic susceptibility−28.8·10−6 cm3/mol (298 K)[7]
CAS Number7439-90-9
History
Discovery and first isolationWilliam Ramsay and Morris Travers (1898)
Main isotopes of krypton
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
78Kr 0.36% 9.2×1021 y[8] εε 78Se
79Kr syn 35 h ε 79Br
β+ 79Br
γ
80Kr 2.29% stable
81Kr trace 2.3×105 y ε 81Br
γ
82Kr 11.59% stable
83Kr 11.50% stable
84Kr 56.99% stable
85Kr syn 11 y β 85Rb
86Kr 17.28% stable
Category Category: Krypton
| references

Krypton (from Ancient Greek: κρυπτός, romanizedkryptos "the hidden one") is a chemical element with the symbol Kr and atomic number 36. It is a colorless, odorless, tasteless noble gas that occurs in trace amounts in the atmosphere and is often used with other rare gases in fluorescent lamps. With rare exceptions, krypton is chemically inert.

Krypton, like the other noble gases, is used in lighting and photography. Krypton light has many spectral lines, and krypton plasma is useful in bright, high-powered gas lasers (krypton ion and excimer lasers), each of which resonates and amplifies a single spectral line. Krypton fluoride also makes a useful laser medium. From 1960 to 1983, the official length of a meter was defined by the 606-nanometer wavelength of the orange spectral line of krypton-86, because of the high power and relative ease of operation of krypton discharge tubes.