Have you observed the following things ?
Copper vessels not cleaned for a long time .

Have you observed the following things ? Old iron bars in the buildings ?

What do you observe in the following Pictures?:

Answer the following questions: Name the vessel having single layer of endothelium.

Give scientific reasons for the following: Copper vessels turn greenish and silver articles turn blackish when kept open in air for a long time.

Which of the following things must not be done at the time of a fire?

Carefully observe the following figure: Name the tehcnique shown in the figure and the scientist who demonstrated this technique for the first time.

Explain the following: Why do silver articles turn balckish while copper vessels turn greenish on keeping in air for a long time?

Answer the following questions : In which instruments have you seen a lens ?

State whether the following statements are true or false. When oils and fats are allowed to stand for a long time, they become rancid.

Suppose you accidentally find an old preserved permanent slide without a lable. In you effort to identify it, you place the slide under microscope and observe the following features: Unicellular Well defined nucleus Biflagellate one flagellum lying longlitudinally and the other transversely. What would you identify it as? Can you name the kingdom it belongs to?