The science of nuclear energy
The science of nuclear energy

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The science of nuclear energy

1.1.2 Common isotopes

Table 1 shows some of the isotopes of the eight lightest elements. Isotopes of the same element have the same atomic number but a different mass number.

Table 1 Common isotopes

Atomic number ZMass number AIsotope nameIsotope symbol
11hydrogencap h 11
12deuteriumcap h 12
23helium-3times times He 23
24helium-4times times He 24
37lithium-7times times Li 37
47beryllium-7 (unstable)times times Be 47
48beryllium-8 (unstable)times times Be 48
49beryllium-9times times Be 49
511boron-11cap b 511
612carbon-12cap c 612
613carbon-13cap c 613
614carbon-14 (unstable)cap c 614
714nitrogen-14cap n 714
816oxygen-16cap o 816

Only the isotopes of hydrogen have their own names. All the H isotopes have one proton but hydrogen has no neutrons, deuterium has one neutron and tritium has two neutrons.

It is worth mentioning that protons and neutrons do themselves have an internal structure and are comprised of even smaller particles, known as quarks.

You will have noticed that some isotopes in the table are labelled unstable. You’ll find out the reason for this later this week. Next, take a short quiz about what you’ve learned so far.


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