TeXercises.com

Radioactivity taken up by cells

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/radioactivity-taken-up-by-cells/

Question

Solution

Short

Video

\(\LaTeX\)

Need help? Yes, please!

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: \(\eta = \dfrac{a}{A} \quad \) \(N_t = N_0 \cdot \text{e}^{-\lambda t} \quad \)

Hide help

No explanation / solution video to this exercise has yet been created.

Visit our YouTube-Channel to see solutions to other exercises.
Don't forget to subscribe to our channel, like the videos and leave comments!

Exercise:
In a certain experiment AzO Ci.eBq of isotopeP half life TO is injected o a medium containing a culture of bacteria. After tO the cells are washed and a detector that is netO efficient counts netO percent of emitted upbeta rays records AO from all the cells. What percentage of the original isotopeP was taken up by the cells?

Solution:
Geg A_ AzO Az T TO T t tO t eta' netO net A_d' AO AQ GesPrecentageeta text no unit The injected Phosphor has an initial activity of A_ AzO Az. This activity decays with the half-life of isotopeP TO. After one hour no significant change in the activity is expected since this one hour is much less than the half-life. A short calculation can confirm that: A_t A_ mathrme^-fracln T t A_ ^-fractT Az mathrme^fracln T t At Observation of the cell culture shows AO i.e. A where only netO is registered. Hence there is a real activity of A_d fracA_d'eta' fracAnet Ad in the cell culture. This is only eta fracA_dA_t fracfracA_d'eta'A_ mathrme^-fracln T t fracA_d'eta' A_ mathrme^-fracln T t approx fracA_d'eta' A_ fracAdAt nta ntap of the theoretical expected activity which means that only .% of the Phosphorus was taken up by the cells. eta fracA_d'eta' A_ mathrme^-fracln T t nta ntap

Meta Information

\(\LaTeX\)-Code

Contained in these collections:

Dosimetrie I by pw

7 | 8
Radioactivity taken up by cells by TeXercises

1 | 4
Dosimetrie 2 by uz

1 | 6

Attributes & Decorations

Tags	bequerel, biology, cells, curie, dosimetry, incorporation, nuclear, physics, radiation, radioactivity, radiometry
Content image
Difficulty	(3, default)
Points	3 (default)
Language	(English)
Type	Calculative / Quantity
Creator	uz
Decoration
File
Link