♦ PHYSICS

1. What enables the eye to focus objects at different distances? 

EXERCISE -III

1. Give one example of each: metals and nonmetals.

Very Short Answer Questions

Question. Why do the non-metals not displace hydrogen from dilute acids? 
Ans. Non-metals being acceptor of electrons, cannot give electrons to the hydrogen ions of acid to reduce them
to hydrogen gas. Hence non-metals do not displace hydrogen from dilute acids.

CBSE Class 10 Biology Management of Natural Resources Worksheet Set C

Management of Natural Resources

Key concepts and terms:

1. Natural Resource: It is stock of the nature such as air, water, soil, minerals, coal, petroleum, forest and wildlife that are useful to mankind in many ways.

2. Pollution: It is defined as the undesirable change in physical, chemical or biological characteristics of our soil, air or water, which harmfully affect human lives or the lives of other species.