In diamonds, cleavage is caused by...

In diamonds, cleavage is caused by...

• A. Relatively wide spaces between some atomic planes
• B. Strong covalent bonds
• C. Tightly bound faces
• D. Disordered lattice

Answer: (A)

Cleavage in diamonds comes from planes of weakness in the crystal lattice. Even though diamonds have an incredibly strong covalent network, the arrangement of carbon atoms creates specific crystallographic planes along which a crack can propagate more easily. These planes are effectively spaced in a way that allows the layers to separate with less energy, producing a clean, flat surface when the crystal fractures. That idea—that there are relatively wide spaces between some atomic planes that guide where a break will occur—is why this option best describes what causes cleavage in diamond. The other ideas don’t fit as well: the overall network is made of strong bonds, so simply “strong covalent bonds” don’t explain easy cleavage; “tightly bound faces” would resist cleavage rather than promote it; and a “disordered lattice” would lead to irregular fracture rather than predictable cleavage along specific planes.

Cleavage in diamonds comes from planes of weakness in the crystal lattice. Even though diamonds have an incredibly strong covalent network, the arrangement of carbon atoms creates specific crystallographic planes along which a crack can propagate more easily. These planes are effectively spaced in a way that allows the layers to separate with less energy, producing a clean, flat surface when the crystal fractures.

That idea—that there are relatively wide spaces between some atomic planes that guide where a break will occur—is why this option best describes what causes cleavage in diamond. The other ideas don’t fit as well: the overall network is made of strong bonds, so simply “strong covalent bonds” don’t explain easy cleavage; “tightly bound faces” would resist cleavage rather than promote it; and a “disordered lattice” would lead to irregular fracture rather than predictable cleavage along specific planes.