If an empty test tube is immersed obliquely in water the immersed portion appears shining - explain why.

When urea is added to water the freezing point decreases. Explain why.

If the plant cell is immersed in water , the water continues to enter the cell until the

One end of a capillary tube of radius r is immersed vertically in water and the mass of water rises in the capillary tube is 5gm. if one end of another capillary tube of radius 2r is immersed vertically in water, what will be the mass of water that will rise in it?

It is better to use detergent than soap in hard water - explain why.

To detect whether current is flowing in a wire or not, the wire is brought near a magnetic needle but the needle shows no deflection. But then the wire is immersed in water kept in a calorimeter, the water gets heated. How could you explain this ?

Suspended from a thread, a piece of iron of mass 160 g remains immersed completely in water. If the specific gravity of iron is 8, calculate the tension in the thread.

Why metallic sodium is kept immersed in kerosene?