The World of Metals and Non-metals — Science STD 7 — Question

Draw a diagram of the oesophagus and stomach to show the movement of food.

What is sewage and sewage treatment?

A sewage treatment plant involves a few steps. Aeration tank, grit and sand removal tank, second sedimentation tank, bar screen, first sedimentation tank.
(i)Arrange all the above steps in the correct order in which they occur in the sewage treatment plant.
(ii)Which step gives most of the sludge?

A car travelling at a speed of 60 km/h takes 20 min to reach its destination. What distance has the car covered?

A shopkeeper has a few bottles of soft drink in his shop. 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 he decide which drink is to be served to whom?

Define photosynthesis along with the equation for the same.

Three liquids are given to you. One is vinegar, another is a baking soda solution, and the third is a sugar solution. Can you identify them only using turmeric paper? Explain.

Why does hot air rise upward?

What are nutrients? Name the different nutrients.

Why do plants use the nitrogen present in soil? How is this nitrogen replenished in the soil?