Câu 7. Cho 4,6 gam một axit cacboxylic no, đơn chức mạch hở tác dụng với 100 ml dd chứa KOH 1M, NaOH 1M. Sau khi phản ứng hoàn toàn thu được 12,4 gam chất rắn khan. CTPT của X là

Ibelieve the answer is weathering,hope my answer has you : ) 

The disturbance is only parallel to the motion of the wave.

Vander waals forces are inter molecular bonds that exist within molecules of the same substance. a water molecule is made up of oxygen and hydrogen atoms which share electrons between each other. the vander waals forces are forces that exist between multitude of different  molecules of water. dipole dipole forces is the type of vander waals force that exist in water. the oxygen atom which is more electronegative pulls the shared electron closer to itself thus generating a partial negative charge while the hydrogen acquire a partial positive charge. these two different charges causes attraction to occur in water molecules.