Problem: The diameter of a rubidium atom is 4.95 Å. We will consider two different ways of placing the atoms on a surface. In arrangement (a), all the atoms are lined up with one another. Arrangement (b) is called a close-packed  arrangement because the atoms sit in the "depressions" formed by the previous row of atoms: By what factor has the number of atoms on the surface increased in going to arrangement (b) from arrangement (a)?

FREE Expert Solution
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FREE Expert Solution

The ratio of atoms in arrangement B to arrangement A is:

  • Atom A: 4.713 x 1014 atoms
  • Atom B: 4.081 x 1014 atoms
80% (439 ratings)
Problem Details

The diameter of a rubidium atom is 4.95 Å. We will consider two different ways of placing the atoms on a surface. In arrangement (a), all the atoms are lined up with one another. Arrangement (b) is called a close-packed  arrangement because the atoms sit in the "depressions" formed by the previous row of atoms: (A) 16 atoms are arranged in a square grid of four rows of four atoms. (B) 16 atoms are arranged in four rows of four, but each row is offset so that the atoms below fit “between” the atoms above rather than directly below them.

By what factor has the number of atoms on the surface increased in going to arrangement (b) from arrangement (a)?

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