# chemistry

posted by Fred

Platinum has a face-centered cubic crystal structure and a density of 21.5 g/cm3. What is the radius of the platinum atom?

1. DrBob222

The fcc has 4 atoms/unit cell.
Mass of 1 atom Pt = 195.08/6.02 x 10^23.
Mass of unit cell is 4 times that.
Then m = volume x density. You know density and mass, calculate volume of unit cell. From volume = a3 you can calculate a (the length of the side).
For a fcc unit cell, 4*radius = a*21/2. You know a and that allows you to calculate radius.
Post your work if you get stuck.
You know

2. Anonymous

98

3. Anonymous,

is not 98. try 139

## Similar Questions

1. ### chemistry

The element platinum has ccp packing with a face-centered cubic unit cell. The density of platinum is 21.5 g/cm3. Calculate the volume (cm3) of the unit cell of platinum.
2. ### Chemistry

Rank the crystal lattice structures in order of decreasing efficiency of space in the structure?
3. ### chemistry

a metal crystallizes in the face centered cubic crystal structure with a unit cell edge of 5.48 x10 power of -8 cm. the density of the metal is 6.90 g per cubic cm. a. what is the mass (g) of a single atom of this element. b. what …
4. ### Chemistry

The crystal structure of cesium chloride (CsCl) is shown in the figure below. The dark spheres represent atoms of Cl. Identify the crystal system: Cubic Tetragonal Orthorhombic Rhombohedral Hexagonal Monoclinic Triclinic Identify the …
5. ### Chemistry

CdO is cubic with a lattice constant a=4.695 A˚ and a density ρ of 8.15 g/cm3. Determine the crystal structure of CdO. Simple Cubic Face Centered Cubic Body Centered Cubic
6. ### Chemistry

CdO is cubic with a lattice constant a=4.695 A˚ and a density ρ of 8.15 g/cm3. Determine the crystal structure of CdO. Simple Cubic Face Centered Cubic Body Centered Cubic
7. ### Chemistry

crystal structure of cesium chloride (CsCl). 1)Identify the crystal system: Cubic Tetragonal Orthorhombic Rhombohedral Hexagonal Monoclinic Triclinic 2)Identify the Bravais lattice: Simple cubic Body Centered Cubic Face Centered Cubic …
8. ### Chemistry

If iridium has a density of 23.3 g/cm3 and forms a face-centered cubic lattice, what is the atomic radius of the iridium atom?
9. ### ***CHEMISTRY HELPPPP!!!!

(b) The density of platinum is 23.4 g/cm3 at 20°C. Calculate the mass of 77.0 cm3 of platinum at this temperature. (c) The density of magnesium is 1.74 g/cm3 at 20°C. What is the volume of 275 g of this metal at this temperature?
10. ### unknown

The density of platinum is 23.4 g/cm3 at 20°C. Calculate the mass of 75.0 cm3 of platinum at this temperature.

More Similar Questions