Carbon and its Compounds — Science STD 10 — Question

What is meant by reproduction?

What is the usual number of valence electrons and valency of group 18 elements of the periodic table?

How is the working nuclear reactor of a power plant shut down in an emergency?

Name the material which is used for making the heating element of an electric iron.

Name a clean gaseous fuel other than LPG and natural gas.

What happens when ethanol is oxidised with alkaline potassium permanganate (or acidified potassium dichromate)? Write the equation of the reaction involved.

What percentage of solar radiation is absorbed by green plants for photosynthesis?

Name the rule which gives the direction of induced current.

State whether the following statements are true or false:

1. A wire with a green insulation is usually the live wire.
2. A miniature circuit breaker (MCB) works on the heating effect of current.