Arseniko

Ang arseniko o arsenik (Kastila: arsenico, Ingles: arsenic) ay isang uri ng elementong kimikal at lasong metaliko. Mayroon itong atomikong bilang na 33, atomikong timbang na 74.992, balensiyang 3 o 5, at sagisag na As. Natutunaw ang abuhing arseniko sa temperaturang 817 °C (habang nasa 28 na presyong atmosperiko, sagisag atm), sumisingaw (sublima) sa temperaturang 613 °C, at may espesipikong grabidad na 5.73. Mayroon itong tatlong anyong alotropiko, na nasa anyong may kulay na dilaw, itim, at abuhing kristalina. Ginagamit ang arseniko bilang insektisidyo o pamatay ng pesteng mga kulisap, pamatay ng mapinsalang mga damo, at inihahalo rin sa mga aloy.^[11]

Arsenic, ₃₃As

Arsenic
Bigkas	/ˈɑːrsənɪk/ (AR-sən-ik) as an adjective: /ɑːrˈsɛnɪk/ (ar-SEN-ik)
Allotropes	kulay-abo (pinakakaraniwan), dilaw, itim (tingnan ang mga alotropo ng arseniko)
Appearance	metallic grey
Standard atomic weight Ar°(As)
	74.921595±0.000006 74.922±0.001 (pinaikli)[1][2]
Arsenic 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 P ↑ As ↓ Sb germanium ← arsenic → selenium
Atomikong bilang (Z)	33
Group	15
Period	4
Block	p-block
Electron configuration	[Ar] 3d10 4s2 4p3
Electrons per shell	2, 8, 18, 5
Physical properties
Phase at STP	solido
Sublimation point	887 K ​(615 °C, ​1137 °F)
Density (at 20° C)	grey: 5.782 g/cm3[3]
when liquid (at m.p.)	5.22 g/cm3
Triple point	1090 K, ​3628 kPa[4]
Critical point	1673 K, ? MPa
Heat of fusion	grey: 24.44 kJ/mol
Heat of vaporization	34.76 kJ/mol (?)
Molar heat capacity	24.64 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 553 596 646 706 781 874
Atomic properties
Oxidation states	−3, −2, −1, 0,[5] +1,[6] +2, +3, +4, +5 (isang katamtamang asidikong oksido)
Electronegativity	Pauling scale: 2.18
Ionization energies	1st: 947.0 kJ/mol 2nd: 1798 kJ/mol 3rd: 2735 kJ/mol (more)
Atomic radius	empirical: 119 pm
Covalent radius	119±4 pm
Van der Waals radius	185 pm
Mga linyang espektral ng arsenic
Other properties
Natural occurrence	primordiyal
Crystal structure	grey: ​rhombohedral (hR2)
Lattice constants	ar = 413.15 pm α = 54.133° pm ah = 375.99 pm ch = 1054.58 pm (at 20 °C)[3]
Thermal expansion	5.6 µm/(m⋅K)[7] (at r.t.)
Thermal conductivity	50.2 W/(m⋅K)
Electrical resistivity	333 nΩ⋅m (at 20 °C)
Magnetic ordering	diamagnetic[8]
Molar magnetic susceptibility	−5.5×10−6 cm3/mol[9]
Young's modulus	8 GPa
Bulk modulus	22 GPa
Mohs hardness	3.5
Brinell hardness	1440 MPa
CAS Number	7440-38-2
History
Discovery	Arabic alchemists (before AD 815)
Isotopes of arsenic t b
Main isotopes[10] Decay abun­dance half-life (t1/2) mode pro­duct 73As synth 80.3 d ε 73Ge γ – 74As synth 17.8 d ε 74Ge β+ 74Ge γ – β− 74Se 75As 100% stable
Kategorya: Arsenic tingnan usapan baguhin | references