Advertisements
Advertisements
प्रश्न
Why are open drains a concern?
उत्तर
Drains that are not covered may get blocked with solid wastes like plastic bags, rags and gravel. Such drains are flooded with dirty water that stagnates and is polluted emitting foul smells and providing breeding grounds to various microbes. Mosquitoes lay eggs and breed causing the spread of diseases like malaria and dengue. Sewage wastes also carry germs that cause serious waterborne diseases like cholera, typhoid, dysentery and jaundice.
APPEARS IN
संबंधित प्रश्न
Use your brain power !
How should roads and footpaths be built to make rainwater seep into the ground?
What works are undertaken to make water available even after the rainy season?
Which, of the following procedures will give you water free from all impurities?
Find out the wrong statement and write it in its correct form.
Chlorination is a commonly used chemical method for killing germs in water.
Explain the traditional ways of purifying water to make it fit for drinking.
The process of adding chlorine in adequate amounts to water is called ______.
______ from the air and sunlight destroy the germs present in water.
Temporary and permanent hardness can be removed by the method of boiling.
Match the following:
| 1. | The density of pure water | a. | Inflammable air |
| 2. | Henry Cavendish | b. | Cathode |
| 3. | Hydrogen | c. | 1 g/cm3 |
| 4. | Negative carbon electrode | d. | Hydrogen |
Name the chemical which converts chlorides and sulphates into insoluble carbonates.
