What is carbon fixation, and how does it relate to photosynthesis?

it is the absorption of co2 from the air; , and it occurs during the light-dependent reactions.
it is the reduction of co2, and it occurs during the calvin cycle.
it is the conversion of co2 into organic compounds, and it forms 3-pga.
it is the production of co2 during regeneration, and it forms rubp.

It is the conversion of CO2 into organic compounds, and it forms 3-PGA.

Answer is to avoid experimental error

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.