Carbon and its Compounds — Science STD 10 — Question

Compare the above system with the probable systems in hilly/ mountainous areas or plains or plateau regions.

If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer.

InMendele′ ev’s Periodic Table the elements were arranged in the increasing order of their atomic masses. However, cobalt with atomic mass of 58.93amu was placed before nickel having an atomic mass of 58.71amu. Give reason for the same.

State two ways in which the energy of sea-waves can be harnessed.

Explain why, electric switches should not be operated with wet hands.

When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name:

1. Substance oxidised, and
2. Substance reduced.

What is sewage? How is sewage disposed of?

State two advantages of using wind energy for generating electricity.