Is vinegar considered as 2 substances already?

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a

Astring vibrates with a frequency of 10 hz. why can't a person hear the sound waves produced by the vibrating string, no matter how large the amplitude of the waves? out! this is homework and due tomorrow! you so much!

Which one of the following substances would be the most soluble in ccl4? na2so4 h2o ch3ch2ch2ch2oh c4h10 hi