MEC681 Quiz 1

Which of the following is nondirectional bonding?

• covalent bonding

• ionic bonding

• Van der Waals bonding

• hydrogen bonding

Why diamond is much harder than graphite although both are made from carbon?

• Both have covalent bonding but diamond has giant covalent bonding.

• Carbon atom bonds to four covalent bonds but diamond has giant structure.

• Diamond forms tetrahedral structure while Graphite forms hexagonal structure.

• Each carbon atom is the same distance to each of its neighboring carbon atoms in graphite but not for diamond.

Which of the following is not true for FCC structure?

• No of atom per unit cell is 4.

• Coordination number is same with HCP structure.

• Examples of materials having FCC structure is silver.

• The packing density is better than HCP structure.

What is the crystallographic plane as shown in the figure?

• (100)

• (010)

• (001)

What is the difference between amorphous solid and crystalline solid?

• Crystalline solid has equally strong bond but not for amorphous solid.

• Amorphous solid has sharp melting point but not for crystalline solid

• Crystalline solid has disorder arrangement of atoms which make it anisotropic

• Amorphous solid has order arrangement of atoms which make it isotropic.