GROUP
1 18
1 Alkali Metals Non-metals 78 Atomic Number 2
H He
PERIOD
1
Pt
Alkaline Earth Metals Halogens
Symbol
Hydrogen
1.008 2 Transition Metals Noble Gases 13 14 15 16 17 Helium
4.003
3 4 5 6 7 8 9 10
Platinum Name
Li Be B C N O F Ne
Other Metals Lanthanides
195.1 Average Atomic Mass
2 Metalloids Actinides
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
6.94 9.012 10.81 12.01 14.01 16.00 19.00 20.18
11 12 13 14 15 16 17 18
3 Na Mg Al Si P S Cl Ar
Sodium
22.99
Magnesium
24.31 3 4 5 6 7 8 9 10 11 12 Aluminium
26.98
Silicon
28.09
Phosphorus
30.97
Sulfur
32.06
Chlorine
35.45
Argon
39.95
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
4 K
Potassium
Ca
Calcium
Sc
Scandium
Ti
Titanium
V
Vanadium
Cr Mn Fe
Chromium Manganese Iron
CoCobalt
Ni
Nickel
Cu Zn Ga Ge As
Copper Zinc Gallium Germanium Arsenic
Se
Selenium
Br
Bromine
Kr
Krypton
39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.93 58.69 63.55 65.39 69.72 72.64 74.92 78.96 79.90 83.79
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
5 Rb
Rubidium
Sr
Strontium
Y
Yttrium
Zr
Zirconium
Nb Mo Tc
Niobium Molybdenum Technetium
Ru Rh Pd Ag Cd
Ruthenium Rhodium Palladium Silver Cadmium
In
Indium
Sn Tin
Sb
Antimony
Te
Tellurium
I
Iodine
Xe
Xenon
85.47 87.62 88.91 91.22 92.91 95.96 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3
55 56 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
6 Cs Ba
Caesium Barium
57-71
Lanthanides
Hf
Hafnium
Ta
Tantalum
W
Tungsten
Re Os
Rhenium Osmium
Ir
Iridium
Pt
Platinum
Au Hg
Gold Mercury
Tl
Thallium
PbLead
Bi
Bismuth
Po
Polonium
At Rn
Astatine Radon
132.9 137.3 178.5 180.9 183.9 186.2 190.2 192.2 195.1 197.0 200.5 204.38 207.2 209.0 (209) (210) (222)
87 88 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118
7 Fr
Francium
Ra
Radium
89-103
Actinides
Rf
Rutherfordium
Db Sg Bh Hs Mt Ds Rg Cn Nh
Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium
Fl
Flerovium
Mc
Moscovium
Lv
Livermorium
Ts Og
Tennessine Oganesson
(223) (226) (265) (268) (271) (270) (277) (276) (281) (280) (285) (284) (289) (288) (293) (294) (294)
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71
La
Lanthanum
Ce
Cerium
Pr
Praseodymium
Nd Pm Sm Eu Gd Tb Dy Ho
Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium
Er Tm Yb
Erbium Thulium Ytterbium
Lu
Lutetium
138.9 140.1 140.9 144.2 (145) 150.4 152.0 157.2 158.9 162.5 164.9 167.3 168.9 173.0 175.0
89 90 91 92 93 94 95 96 97 98 99 100 101 102 103
Ac Th
Actinium Thorium
Pa
Protactinium
U
Uranium
Np Pu Am Cm Bk
Neptunium Plutonium Americium Curium Berkelium
Cf
Californium
Es Fm Md No
Einsteinium Fermium Mendelevium Nobelium
Lr
Lawrencium
(227) 232.0 231.0 238.0 (237) (244) (243) (247) (247) (251) (252) (257) (258) (259) (262)
American Chemical Society www.acs.org/outreach
1 18
1 Alkali Metals Non-metals 78 Atomic Number 2
H He
PERIOD
1
Pt
Alkaline Earth Metals Halogens
Symbol
Hydrogen
1.008 2 Transition Metals Noble Gases 13 14 15 16 17 Helium
4.003
3 4 5 6 7 8 9 10
Platinum Name
Li Be B C N O F Ne
Other Metals Lanthanides
195.1 Average Atomic Mass
2 Metalloids Actinides
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
6.94 9.012 10.81 12.01 14.01 16.00 19.00 20.18
11 12 13 14 15 16 17 18
3 Na Mg Al Si P S Cl Ar
Sodium
22.99
Magnesium
24.31 3 4 5 6 7 8 9 10 11 12 Aluminium
26.98
Silicon
28.09
Phosphorus
30.97
Sulfur
32.06
Chlorine
35.45
Argon
39.95
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
4 K
Potassium
Ca
Calcium
Sc
Scandium
Ti
Titanium
V
Vanadium
Cr Mn Fe
Chromium Manganese Iron
CoCobalt
Ni
Nickel
Cu Zn Ga Ge As
Copper Zinc Gallium Germanium Arsenic
Se
Selenium
Br
Bromine
Kr
Krypton
39.10 40.08 44.96 47.88 50.94 52.00 54.94 55.85 58.93 58.69 63.55 65.39 69.72 72.64 74.92 78.96 79.90 83.79
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
5 Rb
Rubidium
Sr
Strontium
Y
Yttrium
Zr
Zirconium
Nb Mo Tc
Niobium Molybdenum Technetium
Ru Rh Pd Ag Cd
Ruthenium Rhodium Palladium Silver Cadmium
In
Indium
Sn Tin
Sb
Antimony
Te
Tellurium
I
Iodine
Xe
Xenon
85.47 87.62 88.91 91.22 92.91 95.96 (98) 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3
55 56 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86
6 Cs Ba
Caesium Barium
57-71
Lanthanides
Hf
Hafnium
Ta
Tantalum
W
Tungsten
Re Os
Rhenium Osmium
Ir
Iridium
Pt
Platinum
Au Hg
Gold Mercury
Tl
Thallium
PbLead
Bi
Bismuth
Po
Polonium
At Rn
Astatine Radon
132.9 137.3 178.5 180.9 183.9 186.2 190.2 192.2 195.1 197.0 200.5 204.38 207.2 209.0 (209) (210) (222)
87 88 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118
7 Fr
Francium
Ra
Radium
89-103
Actinides
Rf
Rutherfordium
Db Sg Bh Hs Mt Ds Rg Cn Nh
Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium
Fl
Flerovium
Mc
Moscovium
Lv
Livermorium
Ts Og
Tennessine Oganesson
(223) (226) (265) (268) (271) (270) (277) (276) (281) (280) (285) (284) (289) (288) (293) (294) (294)
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71
La
Lanthanum
Ce
Cerium
Pr
Praseodymium
Nd Pm Sm Eu Gd Tb Dy Ho
Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium
Er Tm Yb
Erbium Thulium Ytterbium
Lu
Lutetium
138.9 140.1 140.9 144.2 (145) 150.4 152.0 157.2 158.9 162.5 164.9 167.3 168.9 173.0 175.0
89 90 91 92 93 94 95 96 97 98 99 100 101 102 103
Ac Th
Actinium Thorium
Pa
Protactinium
U
Uranium
Np Pu Am Cm Bk
Neptunium Plutonium Americium Curium Berkelium
Cf
Californium
Es Fm Md No
Einsteinium Fermium Mendelevium Nobelium
Lr
Lawrencium
(227) 232.0 231.0 238.0 (237) (244) (243) (247) (247) (251) (252) (257) (258) (259) (262)
American Chemical Society www.acs.org/outreach
