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Answer» Face centred and end centred unit cells: | Face centred unit cell | End centred unit cell | | 1 | It contains one constituent particle present at the centre of each face, besides the ones present at its corners | It contains one constituent particle present at the centre of any two opposite faces, besides the ones present at its corners. | | 2 | A face centred unit cell has 4 atoms per unit cell. | An end centred unit cell has 2 atoms per unit cell. | | 3 | Face centred unit cell is present in cubic and orthorhombic crystal systems. | End centred unit cell is present in orthorhombic and monoclinic crystal systems | | eg. | Cu, Al, Pt, Au and BaSO4 contain face centred unit cell. | MgSO4.7H2O and Na2SO4. 10H2O contain end centred unit cell. |
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