Question

Q3. Write True and False.
i. Sound travels fastest in air.
ii. Solid expand more than liquids.
iii. In gases the molecules are tightly packed.​

Answer 1

Answer:

I) false

Explanation:

I) Sound waves need to travel through a medium such as a solid, liquid, or gas. The sound waves move through each of these mediums by vibrating the molecules in the matter. The molecules in solids are packed very tightly. Liquids are not packed as tightly as solids. And gases are very loosely packed. The spacing of the molecules enables sound to travel much faster through a solid than a gas. Sound travels about four times faster and farther in water than it does in air.

Hence, the statement is false.

Answer 2

Solids conduct heat better than liquids, which are in turn better conductors than gases. The particles in a solid are most tightly bond and their positions are more or less fixed relative to each other (Fig. 5a). The force between adjacent particles is strong, making heat transfer by collision the most efficient.