Friday, March 18, 2011

Irina Emma and matija's lab

PROJECT
Irina
Emma
Matija
QUESTIONS

1.Does the density of a mineral depend on the size of the mineral sample?

Hypothesis:


It depends on how much air the mineral has inside.   It also depends on the mass divided by volume which equals the density.  To find the density you need to know the mass and volume.

Controlled variables:  How much water is in the graduated cylinder {we will keep this to see the difference between the minerals.} The scale.

Manipulated variables:  The minerals {we will test 3 different kind of minerals so they will have 3 different kind of densities.}

Responding variables:  Density of the minerals

Materials:
  1. Balance
  2. Graduated cylinder
  3. Weighting paper
  4. Samples of minerals


Procedure:
1. Choose the 2 minerals, 3 samples each.
  • WHITE FELDSPAR
  • ORANGE FELDSPAR


2. Find the mass
  • 1. orange feldspar 23.6
  • 2. orange feldspar 34.3
  • 3. orange feldspar 18.6


  • 1. white feldspar 32.1
  • 2. white feldspar 21
  • 3. white feldspar 31.5


3. Find the volume
  • 1.orange feldspar 22 ml
  • 2.orange feldspar 25 ml
  • 3.orange feldspar 14 ml


  • 1. white feldspar 28 ml
  • 2. white feldspar 12 ml
  • 3. white feldspar 20 ml


4. Find the Density
Orange feldspar
1.072
1.3
1.328
White feldspar
1.146
1.75
1.575

5. Make a table with what the density,volume and mass are
























Data analysis
In the data above, I saw a pattern in the density. I saw that the density turned out to all be very similar.  They all started with the number 1.


Conclusion
Does the density of a mineral depend on the size of the mineral sample?  From what I saw in our data of the six different pieces of feldspar, the density was not exactly the same but was very similar as you can see in our graph.  Our hypothesis was half accurate because we said how to figure out how to find the density.  We said what we had to do before we found the density but we did not mention what we thought about the guiding question.  I think we should have. If I ever do a lab like this again, I will pay more attention to the hypothesis.  For this lab, I learned a lot about density.  Earlier this year we did a similar lab with clay.  This lab was a good way to show what we had learned from in the previous lab.  In conclusion, I think that the density of a mineral does not depend on the size because all our minerals where different sizes and shapes.  Some were heavier then other samples but in the end the density was very similar almost the same for all our mineral samples.


Further inquiry
If I had to do this lab again, I would have used a third mineral other than feldspar for example fool’s gold.  I also would have added a second hypothesis when we were halfway through the lab because at the beginning I really did not know what we were doing.  In this lab we used more than one trial so we could compare the minerals densities to find out the answer to the guiding question.  I liked this lab very much because I had the same partner as the previous density lab so it made this lab a whole lot simpler. Feldspar is very common it makes up 60% of earths crust. that is a lot.  The average density of  feldspar is 2.4 to  2.7.  Feldspar is racked 6 out of 10 on the hardness scale. and feldspar is made up crystal's and has a plan cleavage.


http://en.wikipedia.org/wiki/Feldspar






No comments:

Post a Comment