Can someone check to see if my answers look ok.
For the following crystals, explain how their melting points are related to the bonding forces and the crystal structure:
a)Copper,Cu
Copper has metallic bonds between atoms. It can occur as isometric cubic and octahedral crystals, but this is rare. The melting point is 1084.62 °C. The metalic bonds are strong, but the crystals are small and the thermal conductivity is high.
b)Water,H2O
Water as a solid has covalent molecular bonds between atoms and hydrogen bonding between molecules. It has hexagonal crystals. The melting point is 0 °C. Hydrogen bonds are weak so not much energy is required.
c)Sodium chloride,NaCl
Sodium chloride has ionic bonding in cubic close packed (ccp) crystals. The melting point is 801 °C. The temperature for melting must break ionic bonds and electrostatic forces.
d)Diamond,C
Diamond is tetrahedrally covalent bonded carbon atoms in a face centered cubic lattice. It has a melting point of 3547 °C. The covalent bonds are very strong.
Sure, I can help you check your answers.
a) For copper (Cu), you correctly mentioned that it has metallic bonds between atoms. The retention of metallic bonds in copper leads to strong bonding forces. Additionally, the thermal conductivity of copper is high. These two factors, combined with the presence of small crystals, contribute to its relatively high melting point of 1084.62 °C.
b) Regarding water (H2O), you mentioned that it has covalent molecular bonds between atoms and hydrogen bonding between molecules. The presence of hydrogen bonding in water is responsible for its unusual behavior when it comes to melting. Unlike most substances, the melting point of water is 0 °C. This is because hydrogen bonds are relatively weak, resulting in low energy requirements for breaking these bonds and transitioning from solid to liquid.
c) Sodium chloride (NaCl) undergoes ionic bonding and forms cubic close-packed (ccp) crystals. These ionic bonds are strong and involve electrostatic forces. To melt sodium chloride, the temperature must rise high enough to break these ionic bonds and overcome the electrostatic forces. Therefore, the melting point of sodium chloride is 801 °C.
d) For diamond (C), you correctly mentioned that it consists of tetrahedrally covalent bonded carbon atoms in a face-centered cubic lattice. The covalent bonds in diamond are exceptionally strong, which makes diamond one of the hardest substances on Earth. Due to these strong covalent bonds, a significantly high temperature of 3547 °C is required to break the bonds and convert diamond from a solid to a liquid state.
Overall, your answers look accurate and provide a good understanding of how the melting points of these crystals are related to their bonding forces and crystal structures.