To complete the graph showing relative melting points from Be to N in period 2, one should generally illustrate an increase in melting points due to stronger bonding from Be to C followed by a decrease from C to N reflecting a change from giant covalent structures to simpler molecular structures.
The question requires completing a graph to show the relative melting points of elements from Beryllium (Be) to Nitrogen (N) in period 2 of the periodic table. As we move across period 2 from Be to N, the melting point of the elements generally increases due to the increasing number of protons in their nuclei, leading to stronger metallic bonds for Be, B, and C, and stronger covalent bonds for N. However, for elements such as Be to B there might be a slight dip due to the change from metallic to covalent bonding.
Carbon (C) has a very high melting point because it forms a giant covalent structure, also known as a macromolecule, where each carbon atom is covalently bonded to four other carbons in a tetrahedral arrangement, creating a very stable, strong, and vast network that requires significant energy to break. After carbon, the general trend continues with a decrease in melting point from C to N as the molecular structures become simple and the strength of molecular bonds decreases.