The World of Metals and Non-metals — Science STD 7 — Question

What are the different temperature scales used? What are the relations among them?

How do plants get their food?

Razia conducted an experiment in the field related to the rate of percolation. She observed that it took 40min for 200ml of water to percolate through the soil sample. Calculate the rate of percolation.

Unscramble the underlined word in the following sentences :
(i) The discharge of blood in adolescent girls which generally occurs every 28-30 days is nstmnoiaretu.
(ii) The hoarseness in the voice of adolescent boys is due to enlarged iceov xob.
(iii) Secondary sexual characteristics are natural signs that the body is preparing for adulthood and mark the onset of urtvpeb.
(iv) We should say NO to lahoclo and srugd as they are addictive.

In which layer of the soil would you find humus? What is its importance to the soil?

What are the benefits of conducting experiments and asking questions in science? How does this lead to deeper understanding and further exploration?

Monsoon winds are helpful. Do you agree?

A small amount of hydrochloric acid is always produced in the stomach. Is it useful or harmful for us? If excess of acid is produced in the stomach, what should we do?

Complete the following table:
Table: Hot and cold objects

Object	Cold/ Cool	Warm/ Hot
Ice cream	✓
Spoon in a tea cup
Fruit juice
Handle of a frying pan

Explain the following: Bubbles are produced when acetic acid is added to a solution of sodium hydrogen carbonate.