Answer:
[tex]\large\boxed{density=500\ \dfrac{g}{dm^3}}[/tex]
Step-by-step explanation:
[tex]density=\dfrac{mass}{volume}\\\\1L=1dm^3\\1L=1000mL\to1mL=\dfrac{1}{1000}L=0.001L\\1mL=0.001dm^3\\\\\text{We have}\\volume=12.0mL=12.0\cdot0.001dm^3=0.012dm^3\\mass=6g\\\\\text{Substitute}\\\\density=\dfrac{6g}{0.012dm^3}=\dfrac{6\cdot1000}{0.012\cdot1000}\ \dfrac{g}{dm^3}=\dfrac{6000}{12}\ \dfrac{g}{dm^3}=500\ \dfrac{g}{dm^3}[/tex]
