Carbon fixation, reduction phase, carbohydrate formation, and regeneration phase.
It’s gases. Gas particles are always moving around. They have no fixed position and so they have high energies. Density depends on how many particles are present, so if the gas particles move around freely there will be very less density, but if you compress them their particles will increase in number thereby increasing the density
He's actually a biologist who specializes in organic chemistry. But since that's not in the answer choices, i'd recommend putting Scientist or Dermatologist.
