Tissues — Science STD 9 — Question

Name three devices which work on the reflection of sound.

Which subatomic particle whose relative charge is:

1. Chadwick?
2. Thomson?
3. Goldstein?

Name the scientist who gave the laws of motion.

Why do we irrigate our crops?

Fill in the blanks:
_____ nutrients are needed in small quantity for plants and are called _____.

What is meant by the concentration of a solution?

When an incense stick (agarbatti) is lighted in one corner of a room, its fragrance quickly spreads in the entire room. Name the process involved in this.

Write down two advantages of fertilizer over manure.

Which crops are grown in green manured field? Give examples.

Try segregating the things around you as pure substances or mixtures.