Identify the type (or types) of crystalline solid that possess the following properties: good thermal and electrical conductor, can be deformed without breaking.

At 294.5 K, the compound octylcyanobiphenyl undergoes a phase transition from the crystalline solid phase to a liquid crystal phase. Upon increasing the temperature to 306.5 K, it undergoes another liquid crystal phase transition.

Identify which among the following diagrams depicts the liquid crystal formed at 306.5 K.

CO₂ is a molecular compound while SiO₂ is a covalent network solid. Why do carbon and silicon bond differently even though they are both group 4A elements?

Shown below are the electron distributions in the s–d band of three metals. Rank them in order of increasing melting point.

Silicon carbide (SiC) is a ceramic used in electronic applications that operate at high temperatures and high voltages. The β-SiC has a zinc blende structure similar to a diamond wherein each Si atom is bonded tetrahedrally to four C atoms and each C atom is also bonded tetrahedrally to four Si atoms. Which of the following statements explains why silicon carbide is generally more brittle than a metal?

A. When stress is applied to silicon carbide it cannot deform to adapt to stress because the strong ionic bond prevents the atoms from slipping past one another.

B. When stress is applied to silicon carbide it cannot deform to adapt to stress because the strong ionic bond allows the atoms from slipping past one another.

C. When stress is applied to silicon carbide it cannot deform to adapt to stress because the strong covalent bond prevents the atoms from slipping past one another.

D. When stress is applied to silicon carbide it cannot deform to adapt to stress because the strong covalent bond allows the atoms from slipping past one another.

Which of the following characteristics correctly differentiates a ceramic from a metal?

(i) Metals are generally stiffer than ceramics.

(ii) Ceramics generally have higher melting points than metals.

(iii) Metals are more wear-resistant than ceramics.

(iv) Ceramics are more corrosion-resistant than metals.

Classify each of the given solids as molecular, ionic, or atomic: Br₂(s), SO₂(s), MgCl₂(s), Cu(s)