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In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.
The number of atoms in this HCP unit cell is
    Correct answer is '6'. Can you explain this answer?
    Most Upvoted Answer
    In hexagonal systems of crystals, a frequently encountered arrangemen...
    Atom at the face = 2
    Atom at the centre = 3
    Atom at corners = 12
    Total number of atoms = (2 × 1/2) + (3 × 1) + (12 × 1/6) = 6
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    In hexagonal systems of crystals, a frequently encountered arrangemen...
    Hexagonal Close-Packed (HCP) Structure:

    The hexagonal close-packed (HCP) structure is a commonly encountered arrangement of atoms in hexagonal systems of crystals. It consists of a hexagonal prism with top and bottom faces as regular hexagons and three atoms sandwiched between them.

    Arrangement of Spheres:

    In a space-filling model of this structure, each layer is represented by a sphere on a flat surface, surrounded by six identical spheres in the same plane as closely as possible. The second layer is placed over the first layer in a way that each sphere touches three spheres of the bottom layer.

    Identical Third Layer:

    The second layer is then covered with a third layer that is identical to the bottom layer in relative position. This means that the spheres in the third layer are arranged directly above the spheres in the bottom layer, creating a repeating pattern.

    Number of Atoms in the Unit Cell:

    To determine the number of atoms in the HCP unit cell, we need to consider the arrangement of spheres in each layer.

    - First Layer: The first layer consists of a single sphere, which is in contact with six spheres in the second layer.
    - Second Layer: The second layer consists of three spheres, each of which touches three spheres in the first layer and three spheres in the third layer.
    - Third Layer: The third layer is identical to the first layer and also consists of a single sphere, which is in contact with six spheres in the second layer.

    Therefore, the total number of atoms in the HCP unit cell is 1 (first layer) + 3 (second layer) + 1 (third layer) = 5.
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    In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer?
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    In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer?.
    Solutions for In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer? in English & in Hindi are available as part of our courses for JEE. Download more important topics, notes, lectures and mock test series for JEE Exam by signing up for free.
    Here you can find the meaning of In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer?, a detailed solution for In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer? has been provided alongside types of In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice In hexagonal systems of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagons and three atoms are sandwiched in between them. A space-filling model of this structure, called hexagonal close-packed (HCP), is constituted of a sphere on a flat surface, surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer, so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The number of atoms in this HCP unit cell isCorrect answer is '6'. Can you explain this answer? tests, examples and also practice JEE tests.
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