<p> 7th Singapore National Crystal Growing Challenge</p><p>Thank you for participating in this challenge. The details of the competition are given below. For safety reasons, all experiments must be performed under the supervision of a school teacher/lecturer.</p><p>Junior Level</p><p>Potassium Aluminium Sulfate, KAl(SO4)2·12H2O This chemical is commonly called potassium alum. It is easier to grow in all the directions. We are looking for more symmetrical crystals. This is also a factor in this competition. </p><p>Senior Level</p><p>Sodium Bromate, NaBrO3 - Tetrahedral Crystals This belongs to cubic system. These crystals tend to develop veils during growth, unless they are grown quite slowly. Again, very big crystals are not as easy to grow as alum crystals. Tetrahedral crystals have pyramidal shape but more symmetrical or equal-dimensional. Here, shape is also an important factor in the competition.</p><p>Open Level Theme: Cubic Crystals For this category, we will let you do the research to find the most suitable chemical to be used for this purpose. However, you should not use the crystals proposed for the junior and senior levels for this purpose. Remember that the crystal has to be single. Please enter the reasons why you have selected the particular chemical to grow, experimental details and observations, etc. in the display. The main objective of this category is to provide students with an opportunity to exercise their creativity, individuality and scientific knowledge.</p><p>In order to compete in this category, participating institutions should have submitted entries at the junior or senior categories.</p><p>The details about the evaluation rubrics and criteria for judgement of the best crystals (for the year 2004) may be found in our Website: http://www.chemistry.nus.edu.sg/events/ncgc/index.html </p><p>CHEMICAL SUPPLIERS</p><p>Supplier Telephone Fax Number Number Merck (S) Pte Ltd 6890-6638 6890-6636 Regent Chemicals Pte Ltc 6777-5775 6779-3037 Sigma-Aldrich Pte Ltd 6779-1200 6779-1822 Tee Hai Chem Pte Ltd 6862-5655 6862-5855</p><p>Caution: Please get the MSDS (Material Safety Data Sheet) from the supplier along the chemicals.</p>