Heat — Science STD 7 — Question

When chemical reaction takes place, what changes accompany the formation of new substances?

What is the Big Dipper called in Indian astronomy?

One day Sachin had gone to his uncle who lives in a village. He saw there a large number of people defecate in an open area because proper toilet facilities are not there. He wondered about the groundwater contamination, as he studied in his class that this act may cause water-borne diseases. He convinced village people to make toilets in order to avoid such an out break of water-borne diseases.
(i) Name two water-borne diseases.
(ii) What values are shown by Sachin?

What is the actual reason behind improper sanitation?

What is the relation between reflection of light and the image of an object?

Name the process by which common salt is obtained from sea water.

How we can monitor cyclones?

For which purpose sand paper is used?

Measuring of heartbeats is a significant step during health checkups. Name the instrument used for the same.

Name the organ which is located in the chest cavity with its lower tip slightly tilted towards the left.