The marble statutes often slowly get corroded when kept in open for a long time. Assign a suitable explanation.

What happns when washing soda is kept in air for long time?

When NaOH is kept in air for a long time, it becomes wet and then it becomes dry due to formation of a solid crust ouer its surface. Explain the observations.

A tuning fork of frequency 256 Hz is held over the open upper end of a 200 cm long vertical pipe filled with water and the water is slowly darined out through the bottom end of the pipe. Determine the positions of the water level at the time of the first and the second resonances. Neglect the end error. Velocity of sound in air = 320 m* s^(-1) .