Platinum (Pt) has an atomic radius of 139 pm and a density of 21.4 g/cm³. What type of structure will Pt have?

An iron oxide follows the crystal lattice shown below.

Determine the formula for the iron oxide and the oxidation state of iron.

When lead crystallizes, it adopts a face-centered cubic crystal structure. The edge length of the unit cell is 495 pm. Calculate the radius (in pm) and density (in g/cm³) of a lead atom.

Gold crystallizes in a face-centered cubic arrangement with an edge length of 4.07 Å.  Calculate the percentage of Au atoms that are on the surface of a 5.0 nm gold sphere. Use the surface area of a sphere of 4πr², the volume of a sphere of 4/3πr^3, and the diameter of a gold atom of 2.92 Å.

Identify the element and its atomic weight with a density of 10.49 g/cm³ and the edge of the unit cell is 4.08 Å. Assume the element crystallizes in a face-centered cubic lattice.

Label each unit cells with the correct structure (rock salt structure, perovskite structure, zinc blende structure).

Platinum crystallizes with the face-centered cubic unit cell. The radius of a platinum atom is 139 pm. Calculate the edge length of the unit cell and the density of platinum in g/cm³.