The first column in the table is the chemical symbol. The second column is the element's name. The third and fourth columns give Z and A. Where a percentage is given, it is the fraction that isotope represents of the total amount of the element found on earth. e.g. 92.5% of all the lithium found is lithium-7. This is not to say that the two isotopes of lithium are found separately. They are always mixed together in nature, with the given percentages. Where one of several values of A is underlined, it means that this isotope is the most abundant. Where a time is given, this means that the isotope is radioactive, and the time is the half-life.

NUCLEAR TABLE

Z A
H hydrogen 1 1 99.985%
1 2 .015%
1 3 12 years
He helium 2 3 .00014%
2 499.99986%
Li lithium 3 6 7.5%
3 7 92.5%
Be beryllium 4 9
B boron 5 10,11
C carbon 6 12 98.9%
6 13 1.1%
6 14 5730 years
N nitrogen 7 14,15
O oxygen 8 16,17,18
F fluorine 9 19
Ne neon 10 20,21,22
Na sodium 11 23
Ca calcium 20 40,42,43,44,48
Zn zinc 30 64(49%),66,68,70
Br bromine 35 79(51%),81(49%)
35 90 1.9 seconds
Kr krypton 36 84(57%), 86(16%)
36 90 32 seconds
Sr strontium 38 86(10%), 88(82%)
38 90 29 years
Zr zirconium 40 90,91,92,94,96
Sn tin 50112,114,115,116,117,118,119,120(32.6%),122,124
Cs cesium 55 133 100%
55 134 2 years
55 137 30 years
Ba barium 56135, 136, 137, 138, etc.
Nd neodymium 60 144,etc.
Yb ytterbium 70 174,etc.
Pb lead 82206(24%), 207(22%), 208(52%)
Bi bismuth 83 209,etc.
Po polonium 84209 102 years
84210 138 days
U uranium 92235(0.7%) 700 million years
92238(99.3%) 4.5 billion years
Np neptunium 93239 2.4 days
Pu plutonium 94239 24,000 years
94240 6,600 years
Am americium 95243 7,380 years
Fm fermium 100252 25 hours
100254 3.2 hours
Ha hahnium 105262 34 seconds
Mt meitnerium 109268 .07 seconds
114 a few seconds
117297 milliseconds