Our Environment — Science STD 10 — Question

Describe one reaction of ethanol.

What is meant by breathing? What happens to the rate of breathing during vigorous exercise and why?

Why does a new aluminium vessel lose shine so soon after use?

What were the two criteria used by Mendeleev to classify the elements in his periodic table?

Distinguish between the terms ‘overloading’ and ‘short-circuiting ‘ as used in domestic circuits.

Why are forests considered "biodiversity hot spots"? List two ways in which an individual can contribute effectively to the management of forests and wildlife.

a. Write the percentage of (i) solar energy captured by the autotrophs and (ii) energy transferred from autotrophs to the next level in a food chain.
b. What are trophic levels? Why do different food chains in an ecosystem not have more than four to five trophic levels? Give reason.

State two disadvantages of incomplete combustion.

What is a nuclear reactor? What is the fuel used in a nuclear reactor?

Why do green grass plants spring up in dry fields on their own after the rains?