Chapter 2, Problem 90AE

Interpretation Introduction

(a)

Interpretation: The number of rubidium atoms in arrangement A.

Concept introduction: In arrangement A, all the atoms are lined up with one another to form a square grid. The atoms are assumed to be a circle and are aligned in such a way that each atom with diameter $\text{4}\text{.95}\stackrel{\text{o}}{\text{A}}$ can occupy a space of Small Square with side equal to the diameter of the atom.

Interpretation Introduction

(b)

Interpretation: The number of rubidium atoms in arrangement B.

Concept introduction:

In B type arrangement, the atoms sit in a depression and form a close- packing arrangement. The triangle is assumed to be formed by considering the four atoms in the bottom row, three atoms in the third row, two atoms in the middle row, one atom in the first row.

Interpretation Introduction

(c)

Interpretation: The increase in the number of atoms on going from arrangement A to arrangement B and if the density is greater in arrangement A or arrangement B.

Concept introduction:

From going arrangement A to arrangement B,

The increase in the number of atoms is calculated by the by the formula,

$W=\frac{N_1}{N}$