Stars and the solar system. — Science STD 8 — Question

Name the organs which produces sperms in humans.

Which type of friction comes into play when a book kept on cylindrical pencils is moved by pushing?

State whether the following statements are True or False:
The hens give birth to chicks like human beings give birth to babies.

Explain why, water comes out more slowly from an upstairs tap than from a similar tap downstairs.

X is a human activity which will cause an increase in temperature of earth’s atmosphere leading to global warming. It can cause soil erosion making the soil infertile and lead to desertification. It can cause decrease in rainfall but increase the flooding of rivers. It can also affect water cycle and lead to the extinction of many wild species. What is X?

Name the force which always opposes motion.

Name the petroleum product which is commonly used for electric generators.

Name any five objects used in our everyday life which are made of metals.

Name one metal which does not react with dilute hydrochloric acid.

Name any two places in India where natural gas is found.