Question

The atoms of crystalline solid pack together into a three-dimensional array of many small repeating units called unit cells. The simplest of the unit cells are those that have cubic symmetry, with atoms positioned at the corners of a cube. Atoms can also be found in the sides (faces) of the cube, or centered within the body of the cube. It is important to realize that a unit cell is surrounded by other unit cells in every direction. Therefore, face and corner atoms are shared with neighboring unit cells. The fraction varies with the type of atom as shown in the following table.

Masteringchemistry: Post Lecture Homework Chapter 12 Google Chrome https:// Chem 132-05 Post Lecture Homework Chapler 12 t Packing of Sph in Crystalline Solids eres Packing of Spheres in Crystalline Solids Types of unit cells There are three main types ofcubic unit cells: The atoms crystalline solid pack together into a three- dimensional array of many smal repeating units called unit cells. primitive cubic (or simple cubic. The simplest the unit cells are those that have cubic symmetry. body-centered cubic, and with atoms positioned at the corners of a cube. Atoms can also be face-centered cubi ound in the sides (faces) of the cube, or centered within the body of the cube. It is important to realize that a unit cell is sumounded by other unit cells in every direction. Therefore, face and corne Part A atoms are shared with neighboring unit cells. The fraction varies with the type of atom as shown in the following table. Identify the three types of unit cells shown. Type of atom Fraction in unit cell Drag the item to the appropriate bin. face 1 body The size of a unit cell in any given solid can be calculated by using its density. This and the reverse calculation are common test questions in general chemistry courses. -centered ENG Reset Help Face-centered offset next&assignmentProblemID 79458725 previous l 3 of 30 I ned

Answer 1

Beside 8 atoms at 8 corners, there is 6 atoms present at 6 face centres. Beside 8 atoms at 8 corners, there is a atom at body centre Atoms are present only at the 8 corners Hence It is primitive Hence it is Body centred Hence it is Face- centred