Crystals and Cooling Rate Write Up

Discussion Questions > Either a digital or hardy copy please.

1. What is the purpose of this experiment and what do you predict will happen?

2. Make a copy of the table below and fill it in.

3. When your results are done, write a description of what you observed. Be sure to be specific and detailed in your observations.  What did you find? Was it what you expected? How did it compare to the class?  Why might it have been different to expectations?  Compare how your crystals look compared to another Year 8 student Sarah Jones in this video 

4. How does this experiment relate to igneous rocks?  Be sure to include your understanding of the rock cycle and the types of intrusive and extrusive rocks. As part of this explain why some igneous rocks, like pumice or obsidian, appear to have no crystals.  Conversely, rocks like granite seem to be full of many crystals.  Explain why this might be. 
Here is a section on the text-book to help

This resource might help you with your understanding

This resource might also help you

Table for Question 2.

Test Tube	Observations of Ice Crystals	Observations of Air Crystals	Observations of Cotton-Wool Crystals
Rate of Cooling (fast/slow)
Type of igneous rock that cools in similar fashion
Observations of crystals in experiment
Size of crystals in similar igneous rocks (large/medium/unnoticeable)