Question

Living organisms have also got inorganic elements and compounds in them. How do we know this?

Answer 1

Step 1: Weighing
Weigh a small amount of living tissue ( a leaf or liver and this is called wet weight) .

Step 2: Drying
Evaporate all the water and dry that living tissue. The mass of the living tissue after evaporating the water in it is the dry weight.

Step 3: Formation of ash

Now if the tissue is fully burnt, all the carbon compounds are oxidised to gaseous form ($C{O}_2$ , water vapour) and are removed. The remaining compound is called ‘ash’.

Final Answer:This ash contains inorganic elements (like calcium, magnesium etc). Thus by this method we can conclude that living organisms also consist of inorganic elements.