Introduction to Biotechnology — Science STD 9 — Question

Give the properties and uses of Sodium bicarbonate.

What is Teflon? Give its chemical name.

Joule is the unit of …

What are the difficulties in using refracting telescopes?

1. Take two aluminium channels of different lengths.
2. Place the lower ends of the channels on the floor and hold their upper ends at the same height.
3. Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance.

Questions
1. At the moment of releasing the balls, which energy do the balls have?
2. As the balls roll down which energy is converted into which other form of energy?
3. Why do the balls cover the same distance on rolling down?
4. What is the form of the eventual total energy of the balls?
5. Which law related to energy does the above activity demonstrate? Explain.

The potential energy of your body is least when you are …..

Using the chart of ions/radicals and the cross-multiplication method, write the chemical formulae of the following compounds: Sodium bicarbonate

Explain the three different ways to change the velocity.

Why does this happen? (b) Fruits, flowers fall off after a certain period of time.