chemistry

Isotopes of fluorine

Isotopes of fluorine is a chemistry topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Isotopes of fluorine rather than just read about it. In short: Fluorine (9F) has 19 known isotopes ranging from 13F to 31F and two isomers (18mF and 26mF). Only fluorine-19 is stable and naturally occurring in more than trace quantities; therefore, fluorine is a monoisotopic and a mononuclidic element.

Key takeaways

Isotopes of fluorine belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Isotopes of fluorine to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Isotopes of fluorine from memory before moving on to harder problems.

Reference excerpt

Fluorine (9F) has 19 known isotopes ranging from 13F to 31F and two isomers (18mF and 26mF). Only fluorine-19 is stable and naturally occurring in more than trace quantities; therefore, fluorine is a monoisotopic and a mononuclidic element. The longest-lived radioisotope is 18F with a half-life of 109.734 minutes, followed by 17F with 64.37 seconds. These unstable isotopes participate in the CNO cycle within stars. All other fluorine isotopes have half-lives of less than 12 seconds, and most of those less than 1/2 second.

List of isotopes

Fluorine-18

Of the unstable nuclides of fluorine, 18F has the longest half-life, 109.734(8) min. It decays to 18O via β+ decay. For this reason 18F is a commercially important source of positrons. Its major value is in the production of the radiopharmaceutical fludeoxyglucose, used in positron emission tomography in medicine. Fluorine-18 is the second lightest unstable nuclide (after beryllium-8, with 4 protons and 4 neutrons) with equal numbers of protons and neutrons and lightest such with an odd atomic number, having 9 of each. (See also the parity discussion of nuclide stability.)

Fluorine-19 Fluorine-19 is the only stable isotope of fluorine. Its abundance is 100%; no other isotopes of fluorine exist in significant quantities. Its binding energy is 147801.3648(38) keV. Fluorine-19 is NMR-active with a spin of 1/2+, so it is used in fluorine-19 NMR spectroscopy.

Isomers Only two nuclear isomers (long-lived excited nuclear states), fluorine-18m and fluorine-26m, have been characterized. The half-life of 18mF before it undergoes isomeric transition is 162(7) nanoseconds. This is less than the decay half-life of any of the particle-bound fluorine radioisotope nuclear ground states. The half-life of 26mF is 2.2(1) milliseconds; it decays mainly to its ground state of 26F or (rarely, via beta-minus decay) to one of high excited states of 26Ne with delayed neutron emission.

See also Daughter products other than fluorine

Isotopes of neon Isotopes of oxygen

References

Sources Chisté, V.; Bé, M. M. (2011). "F-18" (PDF). In Bé, M. M.; Coursol, N.; Duchemin, B.; Lagoutine, F.; et al. (eds.). Table de radionucléides (Report). CEA (Commissariat à l'énergie atomique et aux énergies alternatives), LIST, LNE-LNHB (Laboratoire National Henri Becquerel/Commissariat à l'Energie Atomique). Archived from the original (PDF) on 11 August 2020. Retrieved 15 June 2011.

Worked examples

Example 1 — a first encounter with Isotopes of fluorine

Start with the simplest possible case. Write down what Isotopes of fluorine claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Isotopes of fluorine before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Isotopes of fluorine ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Isotopes of fluorine

In research: Isotopes of fluorine appears in chemistry research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Isotopes of fluorine in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Isotopes of fluorine is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fluorine, Isotopes of fluorine, Lists of isotopes by element, so understanding it makes those chapters shorter.
In everyday life: Look for Isotopes of fluorine outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Isotopes of fluorine in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Isotopes of fluorine means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Isotopes of fluorine out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Isotopes of fluorine in simple terms?

Why does Isotopes of fluorine matter?

Because it connects several chemistry ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Isotopes of fluorine?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Isotopes of fluorine.