Wastewater Story — Science STD 7 — Question

Research famous scientists (e.g., Marie Curie, Antoine Lavoisier) and their contributions to the understanding of chemical reactions and changes. Create a timeline or a presentation about the history of chemical discoveries.

Soil erosion does not occur easily where the land is covered by vegetation. Do you agree? Explain.

Rahul was a student of Class VII. His father purchased a new bicycle for him on his birthday. After few months, he found that the cycle chain and even the handle gets rusted. His father advised him to apply a coating of paint to the cycle and not to keep it in the open in future.
Now, answer the following Questions:

1. Why his cycle gets rusted?
2. What do you mean by rusting of iron?
3. What values are shown by Rahul’s father?

How you can find out wind direction at a given place.

Is the distilled water acidic/ basic/ neutral? How would you verify it?

Explain how we can plot a graph.

Write one similarity and one difference between the nutrition in amoeba and human beings.

Some birds pooped on Ramesh and to his amazement, the colour of the excretory product was white instead of the usual brown that humans normally have.
Explain the reason behind this.

Label A denotes the lens used in microscope to see objects. Which type of lenses are used in the microscope which helps to see the microbes?