Crime Busters B

[vennowsah]

Ah, thank you! They never checked.
You bring up an interesting point on the cheat sheets. Honestly, I don't exactly understand the point of them, since you can easily just put all your info on the sheet rather than studying for hours to memorize them.
I do enjoy making them though.

[dholdgreve]

I am both confused and concerned about the apparent move by certain event proctors at Invitationals to veer from the posted and paid for national rules and include Bleach (NaClO) as one of the unknown liquids and subject of some of the questions. I've been coaching this event for 17 years... and Bleach has never been one of the accepted liquids that I can recall. When mixed with certain common household chemicals, bleach can release chlorine gas in enough volume to actually be dangerous. I don't remember it ever having been such a problem as it has this year. I'm not sure how to remedy the situation. At both of the invitationals we attended that this had occurred, Crime Busters was being run by a coach of one of the attending teams, so if your coach runs this event, please share with them the concern of using Bleach... It is NOT an approved liquid within the national rules, and can be down right dangerous to those testing it.

Taken from http://voices.yahoo.com/bleach-fumes-sa ... html?cat=5
Using bleach safely
Avoid using bleach in confined spaces such as cupboards where the fumes may be concentrated. If you really must use bleach in such places, wear a good face mask and dilute the product well. Air your rooms well after bleach has been used to dispel the fumes. Don't let bleach come in contact with your skin, especially undiluted bleach.
Bleach is not great for clothes except in very diluted form as it may cause damage to the fabric.
Never, never use bleach mixed with other products as an experiment!
The risk of really hazardous fumes is too great. Use bleach in dilution with water according to the manufacturers instructions. People who have asthma or other breathing difficulties should be particularly careful about using bleach. Also be very careful of bleach splashes. If any should get into your eye, splash it with water for about 15 minutes and get medical help. Get some fresh air after using bleach and if you have any concerns about its effects upon your health consult your physician

From http://www.state.nj.us/health/eoh/cehsweb/bleach_fs.pdf
Mixing bleach and ammonia:
When bleach is mixed with ammonia, toxic gases called chloramines are produced. Exposure to chloramine gases can cause:
•coughing
•shortness of breath
•chest pain
•wheezing
•nausea
•watery eyes
•irritation to the throat, nose and eyes
•pneumonia and fluid in the lungs

Mixing bleach and acids:
When chlorine bleach is mixed with an acid,chlorine gas is given off. Chlorine gas and water combine to make hydrochloric and hypochlorous acids.
Chlorine gas exposure, even at low levels, almost always irritates the mucous membranes (eyes,throat, and nose), and causes coughing and breathing problems, burning and watery eyes, and a runny nose. Higher levels of exposure can cause chest pain, more severe breathing difficulties, vomiting, pneumonia, and fluid in the lungs. Very high levels can cause death. Chlorine can be absorbed through the skin, resulting in pain, inflammation, swelling, and blistering.
Hydrochloric acid also causes burns to the skin, eyes, nose, throat, mouth and lungs.

Mixing bleach and other cleaning products:
Bleach also reacts with some oven cleaners, hydrogen peroxide, and some insecticides

[The Chemist]

Does anyone have good fiber/hair resources?

[ak12]

Hello! Does anyone have a definite way to distinguish between cat, dog, and human hair? I know that cat hair is supposedly the finest and dog hair is the roughest and most rigid and I even know what they are supposed to look like under a microscope(cat - supposed to look like its braided, dog - supposed to look like "flakes" are coming off of it, human - most even). Unfortunately, all the hairs look the same to our team under a microscope and the physical properties can usually only be used when comparing all three. Is there any way you guys know of?

[cupcakegirl]

Hello! Does anyone have a definite way to distinguish between cat, dog, and human hair? I know that cat hair is supposedly the finest and dog hair is the roughest and most rigid and I even know what they are supposed to look like under a microscope(cat - supposed to look like its braided, dog - supposed to look like "flakes" are coming off of it, human - most even). Unfortunately, all the hairs look the same to our team under a microscope and the physical properties can usually only be used when comparing all three. Is there any way you guys know of?

All I can say is look at the microscope again. It takes a decent microscope adequately focused to see what you need to differentiate them. It's pretty rare to get a decent focused microscope at competitions prior to State, in my experience. However, if you do get a good microscope, it's pretty easy and obvious.

[ak12]

Hello! Does anyone have a definite way to distinguish between cat, dog, and human hair? I know that cat hair is supposedly the finest and dog hair is the roughest and most rigid and I even know what they are supposed to look like under a microscope(cat - supposed to look like its braided, dog - supposed to look like "flakes" are coming off of it, human - most even). Unfortunately, all the hairs look the same to our team under a microscope and the physical properties can usually only be used when comparing all three. Is there any way you guys know of?

All I can say is look at the microscope again. It takes a decent microscope adequately focused to see what you need to differentiate them. It's pretty rare to get a decent focused microscope at competitions prior to State, in my experience. However, if you do get a good microscope, it's pretty easy and obvious.

Do you know about what magnification would be required to see the differences? Would 400x be enough? I know we have compound microscopes in our school that reach 400x... Thanks a lot!

[nerdyone]

What liquids are we given to test densities

[Azismith]

Does anyone have past nationals tests for crime busters (or any past tests) that they are willing to share? My partner and I have run out of practice tests...

[Gearbox]

Hello! Does anyone have a definite way to distinguish between cat, dog, and human hair? I know that cat hair is supposedly the finest and dog hair is the roughest and most rigid and I even know what they are supposed to look like under a microscope(cat - supposed to look like its braided, dog - supposed to look like "flakes" are coming off of it, human - most even). Unfortunately, all the hairs look the same to our team under a microscope and the physical properties can usually only be used when comparing all three. Is there any way you guys know of?

All I can say is look at the microscope again. It takes a decent microscope adequately focused to see what you need to differentiate them. It's pretty rare to get a decent focused microscope at competitions prior to State, in my experience. However, if you do get a good microscope, it's pretty easy and obvious.

Do you know about what magnification would be required to see the differences? Would 400x be enough? I know we have compound microscopes in our school that reach 400x... Thanks a lot!

400x is way more than enough. You should be able to see differences with 40x

[zy__karen17]

Hi! Does anybody know if it is required for the analysis to be written in complete sentences? Thanks!