Mass number = number of neutrons + number of protons A = number of neutrons + Z Number of neutrons = A−Z
Atomic number Z | Mass number A | Isotope name | Isotope symbol |
---|---|---|---|
1 | 1 | hydrogen | |
1 | 2 | deuterium | |
2 | 3 | helium-3 | |
2 | 4 | helium-4 | |
3 | 7 | lithium-7 | |
4 | 7 | beryllium-7 (unstable) | |
4 | 8 | beryllium-8 (unstable) | |
4 | 9 | beryllium-9 | |
5 | 11 | boron-11 | |
6 | 12 | carbon-12 | |
6 | 13 | carbon-13 | |
6 | 14 | carbon-14 (unstable) | |
7 | 14 | nitrogen-14 | |
8 | 16 | oxygen-16 |
Atomic number Z | Mass number A | Isotope name | Isotope symbol |
1 | 1 | hydrogen | |
1 | 2 | deuterium | |
2 | 3 | helium-3 | |
2 | 4 | helium-4 | |
3 | 7 | lithium-7 | |
4 | 7 | beryllium-7 (unstable) | |
4 | 8 | beryllium-8 (unstable) | |
4 | 9 | beryllium-9 | |
5 | 11 | boron-11 | |
6 | 12 | carbon-12 | |
6 | 13 | carbon-13 | |
6 | 14 | carbon-14 (unstable) | |
7 | 14 | nitrogen-14 | |
8 | 16 | oxygen-16 |
Atomic number Z | Mass number A | Isotope name | Isotope symbol |
1 | 1 | hydrogen | |
1 | 2 | deuterium | |
2 | 3 | helium-3 | |
2 | 4 | helium-4 | |
3 | 7 | lithium-7 | |
4 | 7 | beryllium-7 (unstable) | |
4 | 8 | beryllium-8 (unstable) | |
4 | 9 | beryllium-9 | |
5 | 11 | boron-11 | |
6 | 12 | carbon-12 | |
6 | 13 | carbon-13 | |
6 | 14 | carbon-14 (unstable) | |
7 | 14 | nitrogen-14 | |
8 | 16 | oxygen-16 |
Electric charge | Notes | |
---|---|---|
Electron | −1 unit | In a neutral atom, number of electrons = number of protons |
Nucleons | Mass number = number of nucleons | |
Proton | +1 unit | Atomic number = total number of protons |
Neutron | 0 | Isotopes of the same elements have different numbers of neutrons |
Element | Isotope | Number of protons | Number of neutrons |
---|---|---|---|
carbon | 6 | 6 | |
calcium | 20 | 20 | |
zinc | 30 | 35 | |
iodine | 53 | 74 | |
uranium | 92 | 146 |
Power production … on such a large scale and probably with so little cost that a sort of industrial revolution could be expected; it appears doubtful for instance whether coal mining or oil production could survive after a couple of years. (Quoted in Weart and Szilard, 1978, p. 39)
Country | Reactors operable | Reactors under construction | Reactors planned | Reactors proposed |
---|---|---|---|---|
US | 99 | 5 | 5 | 17 |
France | 58 | 1 | 1 | 1 |
Japan* | 48 | 3 | 9 | 3 |
Russia | 34 | 9 | 31 | 18 |
South Korea | 23 | 5 | 8 | 0 |
China | 22 | 27 | 64 | 123 |
India | 21 | 6 | 22 | 35 |
Canada | 19 | 0 | 2 | 3 |
UK | 16 | 0 | 4 | 7 |
Ukraine | 15 | 0 | 2 | 11 |
World Total | 437 | 70 | 183 | 311 |