Which material does not melt at any temperature? iron, a metallic element sodium chloride, an ionic compound wood, a mixture of different substances ethanol, a molecular compound

Option (c) is the correct answer.

Explanation:

Wood is a mixture of different substances. Primarily it consists of cellulose, lignin, water etc.

When we heat wood then all these substance oxidize into the atmosphere even before they could melt.

Whereas iron, sodium chloride and ethanol all are the substances which can melt at any temperature.

Thus, we can conclude that out of the given options, wood, a mixture of different substances is a material that does not melt at any temperature.

The pitch of a sound is related to its frequency.

Explanation:

The higher the frequency, the higher the pitch will be

Amplitude is related to how loud a sound is