Molecules in a wave are _____, or stretched apart.

Molecules in a wave are _____, or stretched apart.

• A. compressed
• B. rarefied
• C. vibrating
• D. rotating

Answer: (B)

In a wave, the medium experiences alternating regions of density as particles are pushed together and pulled apart. The term rarefied describes the parts where the particles are spread farther apart, creating lower density. This fits the idea of “stretched apart”. In a longitudinal wave like sound, particles oscillate along the direction of travel, producing both compressions (closer spacing) and rarefactions (wider spacing). The other options don’t match this description: compressed is the opposite, vibrating refers to motion rather than spacing, and rotating isn’t a characteristic feature of these wave patterns.

In a wave, the medium experiences alternating regions of density as particles are pushed together and pulled apart. The term rarefied describes the parts where the particles are spread farther apart, creating lower density. This fits the idea of “stretched apart”. In a longitudinal wave like sound, particles oscillate along the direction of travel, producing both compressions (closer spacing) and rarefactions (wider spacing). The other options don’t match this description: compressed is the opposite, vibrating refers to motion rather than spacing, and rotating isn’t a characteristic feature of these wave patterns.