Why is the grass green?

Question: Why is the grass green?
- Keywords:
  grass,
  green,
  light
Asked by stephthompson to Ryan, Ailsa, Evan, James, Kath on 16 Jun 2011. This question was also asked by 08aglover.
- Ryan Ladd answered on 15 Jun 2011:
  
  A biologist would say – because of a substance called chlorophyll. Chlorophyll is what most plants use to convert light into food.
  
  A physicist would say – because grass reflects the green spectrum of light, absorbing the others. Light from the sun contains all the colours you see in a rainbow and some objects only reflect part of that light, which makes things look the colours that they do!
- Kath O'Reilly answered on 16 Jun 2011:
  
  And why does the grass need to be green? Because the plant absorbs energy that isn’t green, and the green bit is the stuff that’s left!
- Evan Keane answered on 16 Jun 2011:
  
  I think Ryan and Kath’s answers say it all 🙂
- Ailsa Powell answered on 16 Jun 2011:
  
  I would say the best way to answer this question is to combine all the reasons – just because you specialise in one subject you shouldn’t ignore the other reasons – in my area of biochemistry I equally use chemistry, biology and physics to do my research 🙂
  
  So my answer would be that plants contain chlorophyll and the chlorophyll absorbs the red and blue wavelengths of light in the spectrum and doesn’t absorb green light. The green light is reflected back and that’s what we see – a green plant. The chlorophyll then uses the red and blue light it has absorbed to drive a process called photosynthesis which is how the plant produces the food (energy) it needs to grow.

Question: Why is the grass green?

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