A) Using paper chromatography to separate pigments by density
The correct answer is A. The image shows a nuclear fission. This takes place in any of the heavy nuclei after capture of a neutron. This is the opposite of nuclear fusion. In this case, nuclei are broken down into two.
We know 1 mole of any atom or molecules contains 
atom or molecules.
1 mole of HBr i.e 81 gm/mol contains atom or molecules.
So, mass of 
molecules is :
Therefore, mass of molecules is 1.21 gm .
Hence, this is the required solution.
Convection is the transfer of heat by liquid.
Calcium Flouride. It's an ionic bond. Cation + anion with the suffix -ide
