Which One of the Following Statements About Unit Cells and Packing

question 58

Multiple Choice

Which one of the following statements about unit cells and packing in solids is incorrect?

• A)In any unit cell of a solid crystal, each face of the cell must have an opposite face which is equal and parallel to it.
• B)The faces of a unit cell must all be at angles of 90° to each other.
• C)The coordination number of atoms in a close packed metal is 12.
• D)The packing efficiency in fcc structures is higher than in bcc structures.
• E)The packing efficiency in fcc and hcp structures is the same.

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Definitions:

Compounded

A method of calculating interest where the earned interest on an investment is added to the principal, and future interest is calculated on the total amount.

Annuity

A fiscal product designed to emit a stable series of disbursements to an individual, chiefly intended as support for retired people's income.

Perpetuity

A type of annuity that pays an infinite series of cash flows, continuing forever.

Constant Rate

A fixed, unchanging rate at which a specific quantity grows or decays over time.