Why do different instruments have different sound qualities?

Different sounds with the same pitch still sound different because they all have different distribution of frequencies. But this happens because of timbre and every instrument has its own timbre.

a chair, a bed, and a toothbrush

explanation:

i was told this before by a teacher, so yeah

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.