what are the reasons for variation of speed of sound in solid,liquid or gas?Is it because the inter-molecular-space in solid is minimum and the inter molecular force of attraction is the maximum?
The distances between molecules in solids are very small, i.e., solids are more dense as compared to liquids and gases. Because they are so close, than can collide very quickly, i.e. it takes less time for a molecule of the solid to 'bump' into its neighbourhood. Solids are packed together tighter than liquids and gases, hence sound travels fastest in solids. The distances in liquids are shorter than in gases, but longer than in solids. Liquids are more dense than gases, but less dense than solids, so sound travels second fast in liquids. Gases are the slowest because they are the least dense: the molecules in gases are very far apart, compared with solids and liquids.