Questions

We know that, in solids all the particles are packed together and hence sound can travel from one to one very fast.

Hence, speed of sound is maximum in solids and decreses from solids to liquids and liquids to gases. Sound can't travel through vaccum.

When a candidate is officially nominated at the national convention, then the presidential campaign begins.

These mangrove or tidal forests are found in the submerged coastal plains of the Ganga. The name comes from the abundant sundari trees found here. 

Atomic number is the serial number of an element in the periodic classification of elements. It gives the number of protons and also the number of electrons in an atom.