Can't Judge a Powder B

[haven chuck]

How many observations have people been getting?

We had 39 on the state test (described a few posts back), and 49 (i think) on the regionals test, which had H2O, HCl, NaOH, and CaCO4.

[ichaelm]

Thanks, haven chuck!!! Now I finally associate you with your username! XD

[2win]

How many observations have people been getting?

33 at state, and we were gonna write down about 10 more. xD

[DanielleS]

Despite epic failing, we had about 35 observations down.

[suppiechan369]

i heard that the judges are really strict about the differences between "observations" and "inferences". so would it be ok to say that a powder conducts if it gives a reading on the multimeter? or is that an inference?

[haven chuck]

Even if that would be an observation (depends on the judge), you would probably get only 3 or 4 points for the cooresponding answer you would write. Rather, you should write something like "When the conductivity tested is placed in a solution of the powder and [liquid], the light on the conductivity tester blinks very fast." That is for the most basic conuctivity tester, and will almost definitely be 5 points. For one that gives a reading, you could say "The solution of the powder and [liquid] registers a [#] for conductivity."

[karatekid44]

In the rules it states that you could have a device for holding toe powder, wouldn't a graduated cylinder be considered a device for holding the powder? I fought with the judge at states with this.

[haven chuck]

The problem with a graduated cynlinder is that it measures volume, and then you could have more detailed observations than other teams. In the future, test tubes are probably much better and less controversial.

[sciolyandmathcounts]

I'm getting problems with density. I double check my observations but it always says the density is less than 1 yet it sinks in water...........help?????????

[rocketman1555]

I'm getting problems with density. I double check my observations but it always says the density is less than 1 yet it sinks in water...........help?????????

If it sinks in water than the density is greater than one. You should be basing it off of what you observe, not what you calculate. Especially because it would be hard to get an accurate density unless you use a large amount of powder and have something in which you can easily measure a small displacement of the water level. However, you or your partner may be writing the observation down incorrectly.