Answer:
Alright, here's the math:
1. Find the change in volume: 23.312 mL - 23.270 mL = 0.042 mL
2. Calculate the mass of the displaced water: 0.042 mL * 1 g/mL (density of water) = 0.042 g
3. Calculate the volume of the diamond: (23.270 mL - 23.270 mL) + 23.270 mL = 23.270 mL (the diamond displaces all of the water in the graduated cylinder
5. Calculate the density of the diamond: (150 mg) / (23.270 mL) = 0.00646 g/mL
The density of the diamond is 0.00646 g/mL.