Cobalt. 8.9
Silver. 10.5
Lead. 11.3
Platinum. 21.4
Chromium. 7.2
A sample of an unknown metal has a mass of 428 grams and a volume of 20cm^3. What is the metal?
A. Lead
B. Silver
C. Chromium
D. Platinum
To determine the metal, we need to compare its density with the given densities in the question. Density is calculated by dividing the mass of the sample by its volume.
Density = mass / volume
In this case, the density of the unknown metal can be calculated as follows:
Density = 428 grams / 20 cm^3
Density = 21.4 grams/cm^3
Comparing the calculated density (21.4 g/cm^3) with the given densities:
Cobalt: 8.9 g/cm^3
Silver: 10.5 g/cm^3
Lead: 11.3 g/cm^3
Platinum: 21.4 g/cm^3
Chromium: 7.2 g/cm^3
The calculated density matches the density of platinum (21.4 g/cm^3). Therefore, the metal is platinum.
The answer is D. Platinum.