The distance between the centres of carbon & oxygen atom in carbon monoxide gas molecule is 1.13angstrom. Locate the centre of mass of the molecule relative to carbon atom.

-> In the solution of ths ques...m1r1 = m2r2 is considered but hows its equal??

moment of masses about the c.m is zero,   r _cm = m ₁ r ₁ +m ₂ r ₂  / m ₁ + m _{2 .}

  As  r cm = o , (about c.m means ,c.m is taken at origin)hence , m ₁ r₁ + m ₂ r ₂ =o

as per sign convention, m ₁ r ₁ = m ₂  r ₂

This is due to the conservation of centre of mass.

COM=m1r1+m2r2/m1+m2

The centre of mass remains at a fixed position and does not move.

hence COM=0

Hence m1r1+(-m2r2)=0

-ve sign shows that the centre of mass is opposite to one of the atom.