MATERIALS USED IN DAILY LIFE

1. What is cement? Write it's materials.
- Cement is a mixture of calcium aluminate and calcium silicate, which becomes hard and strong when mixed with water and left for some time.
It's raw materials are:
a. Lime stone (CaCO3)
b. Special type of clay (AL2O3. SiO2).

2. Why is gypsum added in cement and lead monoxide in the ordinary glass?
- Gypsum is added in the cement because it increases the quality and setting time of the cement.
- Lead monoxide is added in the ordinary glass because it reduces the temperature of molten material to increase work time with glass.

3. Define cement slurry and cement clinker.
- Cement slurry is defined as the powder mixture of calcium carbonate and clay mixed with water.
- Cement clinker is defined as the reddish colored substance obtained after heating cement slurry at 1600ºC.

4. Write the full form of RCC.
- The full form of RCC is Reinforced Concrete.

5. Write the composition of ordinary glass.
- The composition of ordinary glass are as follows:
a. Silica (50%)
b. Broken glass (25%)
c. Sodium carbonate (15%)
d. calcium carbonate (10%).

6. Which chemical is used to make red, black and blue colored glass?
- The chemicals used to make red and blue colored glass are Copper oxide, Nickel oxide and cobalt oxide respectively.