Acids, Bases and Salts — Science STD 7 — Question

Why is the handle of a metallic kettle covered with strips of cane?

Instead of water explain the reason, why is the mercury used in the thermometer?

What happens when an iron blade of a knife is dipped in a copper sulphate solution? What kind of change takes place?

Name two alternative arrangements for sewage disposal where there is no sewerage system.

Define an electric circuit and give symbols of two electrical components.

Can you give me a name? Solve each of the following riddles by writing the name of the organism and its mode of nutrition. One riddle is solved to help you. I live in water; people keep me in an aquarium and feed me. , .

Draw a labelled diagram of the digestive system of ruminants.

Why bacteria are used in sewage treatment plants?

Design a way to record time using only shadows and a stick.

Differentiate between malleability and ductility.