Crime Busters B

[cupcakegirl]

SO I'm having a reaaly hard time identifying fibers, are there are tricks/tips?

There is a kit on soinc with fibers. Get it, then burn them and see what you can figure out! Also, unless they've changed it since last year, North Carolina's website has some great videos showing you how to burn the fibers and what to look for when you do it. (I think.... I might be remembering wrong, it might not be there)

EDIT: Misunderstanding in the wording fixed

[Skink]

No! Do NOT burn plastics! That releases carcinogens. They, like, kinda cause cancer. Burning is for fibers.

[cupcakegirl]

No! Do NOT burn plastics! That releases carcinogens. They, like, kinda cause cancer. Burning is for fibers.

Um.... I know that.... I'm pretty sure the video was burning fibers... I think they had a video with the density solutions for plastics, not sure. 1 year is too long to remember details of one website xD

[Skink]

I know. I was just mentioning that in case someone else passing through here got confused after reading what you posted

Density sounds right because a sink-float test (yay, preschool!) narrows the plastics down to one of three (out of six total, three with a density >1 and three with a density <1). Then, you need to know the characteristics of each of the three remaining.

[computergeek3]

So we just finished up an Invitational and did terribly.
We had everything we needed for every possible substance, but absolutely NOTHING went right. One material was salt. We were sure it was salt...but no reaction to Iodine. We had a metal that had to be aluminum...had to be! But it couldn't be. Half the clues didn't suggest anybody at all, and the ones that did suggest somebody were evenly divisible so that there was one clue for each suspect. I just went ahead and wrote "the butler did it", since we had no idea who it could possibly be.

Any tips, any tips at all, would be helpful.

Ok, here are a few tips (Click to Show Hidden Text)

1) Salt doesn't react with iodine. The only thing iodine is good for is identifying cornstarch.
2) I would react metals with every reagent available to B Division and make an observations chart.
3) What helps with determining the perpetrator of the crime is going through and circling what incriminates people. This helps with specificity later on when you're analyzing all the evidence that you identified.

Anything else?

[Mlane]

The event descriptions and material on the official website helped my fellow team, I hope this can help others

[ssb4ever]

Hey guys I was wondering about how to identify sample fibers?

Do we have to use the burn test or somethingg

Burn tests are allowed and the proctor should give you matches if they give you a fiber. However, like computergeek3 said, you can use a microscope to identify fibers, although burn tests are far easier. If you can, go for the burn test!

As cupcakegirl said, a proctor might allow you to do burn test, but note that at some competitions, proctors might not allow you to do burn test so your only option is to use a microscope. A tip I suggest you trying is to study the fibers you have thoroughly and feeling their textures and getting to know how they look with or without a microscope. EX: At Churchill Middle School invite we were not allowed to do burn tests, but at Muscatel Middle School invite we were allowed by the proctor to do burn tests, but my partner and I didn't need to use it and got the fibers correct. But if you are allowed to do burn test then that is your best option. GOOD LUCK

[theriddler]

In the rules for Division B, under Polymer Testing/Natural and Man-made Substances (part III) it says "No burn test allowed but burn results may be provided."

[Skink]

In the rules for Division B, under Polymer Testing/Natural and Man-made Substances (part III) it says "No burn test allowed but burn results may be provided."

Careful, bud. That is for section 3.b.iii. which is polymers. Burning plastics is a bad idea. That regulation only refers to plastics.

In fact, check 2.b.vii. Candles or matches will be provided by supervisors if fibers are tested on, which is what we're talking about.

[ssb4ever]

Does anyone know anything about doing soil compositions and comparing them to suspects???