u/Sora1276

I did an experiment where we measured how well plastic (LDPE) blocks beta radiation from a strontium-90 source. Took background readings, source readings with no absorber, and 10 readings with increasingly thick LDPE between the source and Geiger counter.

Corrected for background radiation, plot the log of that count rate against LDPE thickness - trying to find what absorber thickness would be needed to stop the particles (x-intercept - ln(N(x)) = 0), correlating with Sr-90 and Y-90 β particles (2mm and 11mm into our sample).

My final value came out as 14.8 ± 1.0 mm, compared to the suggested 11 mm Y-90 range. Would anyone have suggestions as to what might cause the elevated value. To preface, my lab instructor ran through the test in his own time and derived a similar value to me.

My R²=0.97, nothing in my data suggests random error is the cause.

Leaves me a little stumped as to what I write in limitations, discussion, etc.

Thank you!

Not sure if this is the right place to ask this, but I did an experiment where we measured how well plastic (LDPE) blocks beta radiation from a strontium-90 source. Took background readings, source readings with no absorber, and 10 readings with increasingly thick LDPE between the source and Geiger counter.

Corrected for background radiation, plot the log of that count rate against LDPE thickness - trying to find what absorber thickness would be needed to stop the particles (x-intercept - ln(N(x)) = 0), correlating with Sr-90 and Y-90 β particles (2mm and 11mm into our sample).

My final value came out as 14.8 ± 1.0 mm, compared to the suggested 11 mm Y-90 range. Would anyone have suggestions as to what might cause the elevated value. To preface, my lab instructor ran through the test in his own time and derived a similar value to me.

My R²=0.97, nothing in my data suggests random error is the cause.

Leaves me a little stumped as to what I write in limitations, discussion, etc.

Thank you!

I was using Vivaldi for a while before switching back to Firefox due to extension issues. Really enjoy using Vivaldi's tab stacking function, though. Is there any extension that I can use with Firefox to get a similar experience?

Edit: Obviously tab groups exist in Firefox, but they're sort of just a slightly more annoying, less enjoyable version for my use case. Not auto-collapsing, being shown as a coloured box instead of current tab, etc.

About to finish my first semester. I've been planning on majoring in chemistry, but I'm having a sudden change of heart. My only math knowledge is completing MZB103 and MZB104, and I don't really have anything else as I've been out of high school a long time.

If I were to change my major to physics this semester, for anyone that has taken either of these classes, would MXB105/6 be manageable? Thank you in advance!

Assessment due dates have been extended until Wednesday. Do you think there'd be any change for an online chem quiz I have on Tuesday? I didn't attend the lecture in person this week and didn't get around to watching the recording before it went down.

It seems like I can access the lecture from Echo360 still, but canvas has a bunch of material to work through each week which is as important as the classes, if not more.

If the quiz is shifted from Tuesday to Wednesday, it doesn't really make up for 4-5 days without that study material. I guess I can definitely go learn the content through other means, which I will, but I'm just wondering if there's any info on it.