[Cammy34349 (OP)]

Hey, Studying for my GCSEs at the moment (uk high school exams), and have been trying to figure out something about isotopes but my teachers are all on holiday      I'm sure to most of you this is a very basic question, but to me help would be greatly appreciated

when it comes to isotopes, can a certain element e.g. a block of zinc, contain multiple isotopes within that sample, like is a block of carbon-13 called carbon-13 because it only contains that isotope OR is it because when balancing out that particular isotope it ends up at that isotope (some Carbon-12 and some Carbon-14)

[Janus]

Any random sample of an element can contain a number of isotopes.  For example, Uranium in its natural form is made up of both U-238 and U-235.  Since only U-235 is fissile, "raw" Uranium has to be enriched (The percentage of U-235 increased) in order for it to be useful for power plants or nuclear weapons(Nuclear weapons need a much higher enrichment than reactor fuel needs)

[evan_au]

If you look up the isotopes of an element in Wikipedia, you will see a typical abundance in nature for the common isotopes.

They also provide a larger table that includes all the isotopes that are too unstable to have any measurable concentration in nature.

See, for example Oxygen, which has 3 stable isotopes in nature, and 13 unstable isotopes which have been studied.
https://en.wikipedia.org/wiki/Isotopes_of_oxygen

[alancalverd]

The standard Periodic Table lists the mean atomic weight of naturally-occuring elements. There are several decimal points in all entries because the natural or chemically refined material rarely consists of a single isotope - you need to do some additional physics to separate them.