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Periodic trend

Atomic Mass

The average mass of one atom, weighted across naturally occurring isotopes. Climbs steadily with atomic number.

Atomic Mass plotted against atomic numberAtomic Mass for 118 of the 118 elements, from 1.008 to 294.000 u. The average mass of one atom, weighted across naturally occurring isotopes. Climbs steadily with atomic number.12345671.00874.256147.504220.752294.000 Hydrogen (H): 1.008 u Helium (He): 4.003 u Lithium (Li): 6.940 u Beryllium (Be): 9.012 u Boron (B): 10.810 u Carbon (C): 12.011 u Nitrogen (N): 14.007 u Oxygen (O): 15.999 u Fluorine (F): 18.998 u Neon (Ne): 20.180 u Sodium (Na): 22.990 u Magnesium (Mg): 24.305 u Aluminium (Al): 26.982 u Silicon (Si): 28.085 u Phosphorus (P): 30.974 u Sulfur (S): 32.060 u Chlorine (Cl): 35.450 u Argon (Ar): 39.948 u Potassium (K): 39.098 u Calcium (Ca): 40.078 u Scandium (Sc): 44.956 u Titanium (Ti): 47.867 u Vanadium (V): 50.942 u Chromium (Cr): 51.996 u Manganese (Mn): 54.938 u Iron (Fe): 55.845 u Cobalt (Co): 58.933 u Nickel (Ni): 58.693 u Copper (Cu): 63.546 u Zinc (Zn): 65.382 u Gallium (Ga): 69.723 u Germanium (Ge): 72.631 u Arsenic (As): 74.922 u Selenium (Se): 78.972 u Bromine (Br): 79.904 u Krypton (Kr): 83.798 u Rubidium (Rb): 85.468 u Strontium (Sr): 87.621 u Yttrium (Y): 88.906 u Zirconium (Zr): 91.224 u Niobium (Nb): 92.906 u Molybdenum (Mo): 95.951 u Technetium (Tc): 98.000 u Ruthenium (Ru): 101.072 u Rhodium (Rh): 102.906 u Palladium (Pd): 106.421 u Silver (Ag): 107.868 u Cadmium (Cd): 112.414 u Indium (In): 114.818 u Tin (Sn): 118.711 u Antimony (Sb): 121.760 u Tellurium (Te): 127.603 u Iodine (I): 126.904 u Xenon (Xe): 131.294 u Cesium (Cs): 132.905 u Barium (Ba): 137.328 u Lanthanum (La): 138.905 u Cerium (Ce): 140.116 u Praseodymium (Pr): 140.908 u Neodymium (Nd): 144.242 u Promethium (Pm): 145.000 u Samarium (Sm): 150.362 u Europium (Eu): 151.964 u Gadolinium (Gd): 157.253 u Terbium (Tb): 158.925 u Dysprosium (Dy): 162.500 u Holmium (Ho): 164.930 u Erbium (Er): 167.259 u Thulium (Tm): 168.934 u Ytterbium (Yb): 173.045 u Lutetium (Lu): 174.967 u Hafnium (Hf): 178.492 u Tantalum (Ta): 180.948 u Tungsten (W): 183.841 u Rhenium (Re): 186.207 u Osmium (Os): 190.233 u Iridium (Ir): 192.217 u Platinum (Pt): 195.085 u Gold (Au): 196.967 u Mercury (Hg): 200.592 u Thallium (Tl): 204.380 u Lead (Pb): 207.210 u Bismuth (Bi): 208.980 u Polonium (Po): 209.000 u Astatine (At): 210.000 u Radon (Rn): 222.000 u Francium (Fr): 223.000 u Radium (Ra): 226.000 u Actinium (Ac): 227.000 u Thorium (Th): 232.038 u Protactinium (Pa): 231.036 u Uranium (U): 238.029 u Neptunium (Np): 237.000 u Plutonium (Pu): 244.000 u Americium (Am): 243.000 u Curium (Cm): 247.000 u Berkelium (Bk): 247.000 u Californium (Cf): 251.000 u Einsteinium (Es): 252.000 u Fermium (Fm): 257.000 u Mendelevium (Md): 258.000 u Nobelium (No): 259.000 u Lawrencium (Lr): 266.000 u Rutherfordium (Rf): 267.000 u Dubnium (Db): 268.000 u Seaborgium (Sg): 269.000 u Bohrium (Bh): 270.000 u Hassium (Hs): 269.000 u Meitnerium (Mt): 278.000 u Darmstadtium (Ds): 281.000 u Roentgenium (Rg): 282.000 u Copernicium (Cn): 285.000 u Nihonium (Nh): 286.000 u Flerovium (Fl): 289.000 u Moscovium (Mc): 289.000 u Livermorium (Lv): 293.000 u Tennessine (Ts): 294.000 u Oganesson (Og): 294.000 u Period
118 of 118 elements have a measured value.1.008 – 294.000 u

Highest

  1. 1Ts Tennessine294.000
  2. 2Og Oganesson294.000
  3. 3Lv Livermorium293.000
  4. 4Fl Flerovium289.000
  5. 5Mc Moscovium289.000

Lowest

  1. 1H Hydrogen1.008
  2. 2He Helium4.003
  3. 3Li Lithium6.940
  4. 4Be Beryllium9.012
  5. 5B Boron10.810

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