The Ever-Evolving World of Science — Science STD 7 — Question

Boojho’s uncle was hospitalised and put on dialysis after a severe infection in both of his kidneys.
When does it become necessary to take such a treatment?

Give the pathway of air in the human respiratory system.

Explain why: An antacid tablet is taken when you suffer from acidity.

The concave reflecting surface of a torch got rusted. What effect would this have on the beam of light from the torch?

How do the movements of Earth and Moon affect life on Earth?

What is respiration in plants? How is it different from photosynthesis? Explain the importance of both processes.

Boojho made light from a laser torch to fall on a prism. Will he be able to observe a band of seven colours? Explain with a reason.

Mention any two letters of English alphabet whose image formed in a plane mirror appears exactly similar to the letters.

Explain why burning of wood and cutting it into small pieces are considered as two different types of changes?

While going for a school picnic, Paheli decided to note the reading on the odometer of the bus after every 30 min till the end of the journey. Later on she recorded her readings in table.
Odometer reading at different times of the journey

Time (AM)	Odometer readings	Distance from the starting point
8:00	36540 km	0 km
8:30	36560 km	20 km
9:00	36580 km	40 km
9:30	36600 km	60 km
10:00	36620 km	80 km

(i) Can you tell how far was the picnic spot from the school?
(ii) Can you calculate the speed of the bus?
(iii) Looking at the table, Boojho asked Paheli whether she can tell how far they would have travelled till 9:45 AM.