StackOverflow Buoyancy Viscosity doubt correction

• Stress / strain due to intermolecular forces
• Viscosity due to intermolecular forces
• Pressure due to intermolecular forces
• Density due to intermolecular forces

• Buoyancy due to pressure and density

• How do viscosity and density arise from intermolecular forces?

  • Why can't viscosity be described in terms of density?