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Zellen nehmen radioaktive Substanz auf

About points...

We associate a certain number of points with each exercise.
When you click an exercise into a collection, this number will be taken as points for the exercise, kind of "by default".
But once the exercise is on the collection, you can edit the number of points for the exercise in the collection independently, without any effect on "points by default" as represented by the number here.

That being said... How many "default points" should you associate with an exercise upon creation?
As with difficulty, there is no straight forward and generally accepted way.
But as a guideline, we tend to give as many points by default as there are mathematical steps to do in the exercise.
Again, very vague... But the number should kind of represent the "work" required.

About difficulty...

We associate a certain difficulty with each exercise.
When you click an exercise into a collection, this number will be taken as difficulty for the exercise, kind of "by default".
But once the exercise is on the collection, you can edit its difficulty in the collection independently, without any effect on the "difficulty by default" here.
Why we use chess pieces? Well... we like chess, we like playing around with \(\LaTeX\)-fonts, we wanted symbols that need less space than six stars in a table-column... But in your layouts, you are of course free to indicate the difficulty of the exercise the way you want.

That being said... How "difficult" is an exercise? It depends on many factors, like what was being taught etc.
In physics exercises, we try to follow this pattern:

Level 1 - One formula (one you would find in a reference book) is enough to solve the exercise. Example exercise

Level 2 - Two formulas are needed, it's possible to compute an "in-between" solution, i.e. no algebraic equation needed. Example exercise

Level 3 - "Chain-computations" like on level 2, but 3+ calculations. Still, no equations, i.e. you are not forced to solve it in an algebraic manner. Example exercise

Level 4 - Exercise needs to be solved by algebraic equations, not possible to calculate numerical "in-between" results. Example exercise

Level 5 -
Level 6 -

Exercise

https://texercises.com/exercise/zellen-nehmen-radioaktive-substanz-auf/

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The following quantities appear in the problem: Zeit \(t\) / Zerfallskonstante \(\lambda\) / Anzahl \(N\) / Verhältnis / Anteil \(\eta\) /

The following formulas must be used to solve the exercise: \(\eta = \dfrac{a}{A} \quad \) \(N_t = N_0 \cdot \text{e}^{-\lambda t} \quad \)

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Exercise:
In einem Experiment wird isotopeS mit einer Halbwertszeit von .d und einer Anfangsaktivität von kBq in ein Medium mit einer Bakterienkultur injiziert von der man weiss dass sie .% des Schwefels über Stoffwechselprozesse aufnimmt. Wie lange muss man warten bis ein Detektor der % der emittierten upbeta^--Strahlung nachweist noch numpr Impulse pro Sekunde misst?

Solution:
boxGegeben T .d .es A_' kBq .eBq eta .% . eta' % . A_t' Bq boxGesucht textWartZeit tsis Die Bakterienkultur hat anfänglich eine Aktivität von A_ eta A_' . .eBq .eBq über Stoffwechselprozesse aufgenommen. Die in der Bakterienkultur nach der gesuchten Zeit noch vorhandene Aktivität beträgt: A_t fracA_t'eta' fracBq. Bq Bis die anfängliche Aktivität A_ auf den als letztes berechneten Endwert abgeklungen ist dauert es: t fracTln lnfracA_A_t fracTln lnfraceta' eta A_'A_t' T log_lefteta' eta fracA_'A_t'right frac.dln lnfrac.eBqBq frac.esln lnfrac.eBqBq .d .es boxbox t fracTln lneta' eta fracA_'A_t' T log_lefteta' eta fracA_'A_t'right .d .es

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Radioactivity taken up by cells by TeXercises

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Attributes & Decorations

Tags	biologie, physik, prozent, radioaktivität, radiometrie, wirksamkeit, zellen, zerfallsgesetz
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Difficulty	(3, default)
Points	3 (default)
Language	(Deutsch)
Type	Calculative / Quantity
Creator	uz
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