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Topic: Toothpaste with fluorine  (Read 6771 times)

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Offline Big-Daddy

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Re: Toothpaste with fluorine
« Reply #15 on: May 04, 2013, 06:12:48 AM »
I think they should have just said half of the total mass of F in the toothpaste is in Na2PO3F and half is in F.
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Offline Rutherford

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Re: Toothpaste with fluorine
« Reply #16 on: May 04, 2013, 07:53:14 AM »
The goal of the authors of competition problems is to make the text as much ambiguous as it is possible :).
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Offline Corribus

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Re: Toothpaste with fluorine
« Reply #17 on: May 04, 2013, 12:03:49 PM »
Writing good test questions isn't trivial.  What seems well worded to one person is often ambiguous to another.  That's why good test-writers will have their questions peer-reviewed like any other document.  It's especially important in competitions.
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What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman
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