Compounds are molecules with 2 or more elements
So the answer would be the third one
CO2;H2O
Answer:
Same frequency, shorter wavelength
Explanation:
The speed of a wave is given by


where,
f = Frequency
= Wavelength
It can be seen that the wavelength is directly proportional to the velocity.
Here the frequency of the sound does not change.
But the velocity of the sound in air is slower.
Hence, the frequency remains same and the wavelength shortens.
Buddy, I think you need to evaluate your question and fix it. Because it's not making any sense, whatsoever.