1. Chromium CHEMISTRY PROJECT Class: 5E Name: Ho Ka Yu Leung Shu Ting Wong Yuen Ting Yip Chi Chin

2. BASIC INFORMATION Symbol : Cr Atomic Number : 24 Name Origin: From the Greek word chró ̱ ma Obtained From: Chromite Discovered By : Nicholas Louis Vauquelin

3. PROPERTIES a lustrous steel-gray color which takes a high polish hard and resistant to corrosion has a high melting point, stable crystalline structure, and moderate thermal expansion. All chromium compounds are colored. Chromium compounds are toxic.

4. USE OF CHROMIUM IN OUR DAILY LIFE

5. Drilling Mud - prevent corrosion of steel under wet condition Laboratory Glassware - chromic acid is a powerful oxidizing agent Wood Preservative - protect wood from decay fungi, wood attacking insects

6. Metallurgy - Decorative chrome plating on a motorcycle Dye and Pigment - used for school bus in the US and Postal Service in Europe Tanning - stabilizes the leather by linking the collagen fibre

7. HEALTH EFFECTS Shortages may cause heart conditions, disruptions of metabolisms and diabetes Uptake of chromium (III) can cause instance skin rashes Chromium (VI) in leather products can cause allergic reactions Breathing in chromium (VI) can cause nose irritations

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