Explain why (a) A diamond glitters in a brightly lit room, but not in a dark romm.
(b) A crack in window pane appears silvery.
(c ) The bubbles of air rising up in a water tank appear silvery when viewed from top.

Explain why (a) A diamond glitters in a brightly lit room, but not in a dark room. (b) A crack in a window pane appears silvery. ( c) The bubbles of air rising up in a water tank appear silvery when viewed from top.

Why does water tank appear shalleower when veiwed from the top ?

Explain why an air bubble in water rises from bottom to top and grows in size?

Paheli kept some water in a beaker for heating. She observed that tiny bubbles appeared before the water started to boil. She boiled the water for about 5 minutes and filled it in a bottle up to the brim and kept the bottle air tight till it cooled down to room temperature (a) Why did the tiny bubbles appeared ? (b) Do you think tiny bubbles will appear on heating the water taken out from the bottle? Justify your answer.

Assertion : An empty test tube dipped into water in a beaker appears silver, when viewed from a suitable direction. Reason : Due to refraction of light, the substance in water appears silvery.

Bubbles of air coming out through water in glass vessel appears silvery to an observer standing by the sides Explain the reason.