Key Stage 4
Meaning
Isotopes are atoms with the same number of protons (the same element) but a different number of neutrons.
About Isotopes
- Each element has many isotopes but some are stable and others are unstable so they decay quickly into other isotopes or a different element.
- Different isotopes of the same element have the same atomic number but different atomic mass due to the different numbers of neutrons.
Examples
| Hydrogen-1 | Hydrogen-2 | Lithium-7 | Lithium-6 |
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| Hydrogen always has 1 proton but isotope there are no neutrons. | Hydrogen always has 1 proton but in this isotope there is 1 neutron. This isotope of Hydrogen is known as Deuterium. | Lithium always has 3 protons but in this isotope there are 4 neutrons. | Lithium always has 3 protons but in this isotope there are 3 neutrons. |