Exploring Substances: Acidic, Basic, and Neutral — Science STD 7 — Question

You have been asked to maintain a garden. How will you minimise the use of water?

Classify the changes involved in the following processes as physical or chemical changes.
(a) Photosynthesis
(b) Dissolving sugar in water
(c) Burning of coal
(d) Melting of wax
(e) Beating aluminium to make aluminium foil
(f) Digestion of food

Ruminants such as cows and buffaloes swallow their food hurriedly and then sit restfully and chew their food. Can you reason why?

Sketch the reproductive parts of a flower.

Dorji has a few bottles of soft drink in his restaurant. But, unfortunately, these are not labelled. He has to serve the drinks on the demand of customers. One customer wants acidic drink, another wants basic and third one wants neutral drink. How will Dorji decide which drink is to be served to whom?

A girl was suffering from cold and was sneezing continuously. She joined her family at dinner and suddenly started sneezing without covering her nose, thus spreading particles all over the place.
On realising her mistake, said sorry and next time covered her nose.
(i) During sneezing, what are the precautionary steps to be followed?
(ii) Is sneezing a respiratory process?

A person met with an accident while driving. After examination, the doctor told him that since he got a fracture in the wrist, operation would be required. After the operation, the patient was put on a glucose drip and was not given food for a few hours.
(i) Why was the patient not given food directly?
(ii) How does the glucose help the patient recover?

What happens to the food in mouth and oesophagus of the digestive tract?