What are surfactants?

Which of the following is not a surfactant?

In alveoli, surfactant is produced by

The following are the two statements regarding alveolar fluid: (a) It contains a surfactant that reduces the tendency of alveoli to collapse. (b) Surfactant in the alveolar fluid lowers the surface tension. Of the above statements, which one of the following options is correct?

10 ml of 1 millimolar surfactant solution forms a monolayer covering 0.24cm^(2) on a polar substrate. If the polar head is approximated as a cube. Consider the surfactant is adsorbed only on one face of the cube. What is the edge length of cube? (Answer should be in pm and assume Avogadro's number =6xx10^(23) ).

What are histones? What are their functions?

What is an error? What are constant errors?

What is a unit? What are its characteristics?