5. What is dam? Why do we seek to build large dams? While building large dams which three main
problems should particularly be addressed to maintain peace among local people ? Mention them.
15. (a) Write the steps involved in the extraction of pure metals in the middle of the activity series from
Answers
Answer:
Danm is a infrastructure which is built for holdings large water bodies.
the problem faced during building large dams
1 It takes a large space
2.It has difficult to set a good location for its construction
Answer: Dam is a barrier across flowing water that stops,directs the flow of water.
large dams are built to conserve large amount of water.
three problems-
they should be given money for property loss.
they should be ensured of providing new shelter.
they should be given agricultural land.
The carbonate ores are changed into oxides by heating strongly in limited air. This process is called calcination. ZnCO_3(s) \xrightarrow {heat} ZnO(s) arrow heat +CO_2 (g)ZnCO3
(g)
The metal oxides are then reduced to the corresponding metals by using suitable reagents such as carbon. For, example, when zinc oxide is heated with carbon, it is reduced to metallic zinc.
ZnO + C arrow Zn + COZnO+C→Zn+CO