Water: A Precious Resource — Science STD 7 — Question

Untreated human excreta is a health hazard. Explain.

Draw and label the stages of the water cycle. Colour it as well.

Last Sunday Girish's mother, Priyanka was preparing the dinner in her kitchen for Girish and his father. Both of them were feeling so much hungry and they sat ideally on their respective chairs and having empty plates and spoons on their dinning table. They were shouting like a 5 years old child that they wanted the dinner so eagerly to fulfil their stomach. After sometime, Girish's mother served the cooked food to both of them and when Girish was just about to eat the rice with the help of spoon, he noticed that the spoon has such a shining surface that it reflected the light rays incident on it.
(i) Explain the importance of shining surface in the reflection of light.
(ii) Name the type of spherical mirror represented by the shining steel spoon.
(iii) Mention the values shown by Priyanka here towards her family

Outline your role as an active citizen in relation to sanitation.

What are the functions of ribs and diaphragm during breathing? Describe their functioning.

Rahul left his bicycle outside in the garden during the rainy season. After a few weeks, he noticed that the handle and chain of the bicycle had developed a reddish-brown layer. His science teacher told him that this is a common problem with iron objects and explained how to prevent it.
Q.1. What is the reddish-brown substance seen on the bicycle called?
Q.2. What are the two conditions required for rusting of iron?
Q.3. Name two methods that Rahul can use to prevent the rusting of his bicycle.

Describe how crystals of copper sulphate are prepared.

Write short notes on Short Circuiting.

Why is it called an artery if it does not carry oxygen-rich blood?