Question

Non-metals are less dense and have low boiling and melting points as compared to metals.
A- True
B- False

Answer 1

Hint: Think about the process of melting and boiling. What are the changes before and after these processes and what are the forces we need to overcome to complete these processes? Try to find out the relation between density and packing.

Complete step by step solution:
We know that most metals are solids due to close packing. Due to the formation of metallic bonds between a large number of atoms. In metallic bonds electrons from metal atoms and metal ions form close-packed structures such as Cubic close-packed, Hexagonal close-packed, Body-centered cubic. Metals have a large number of attractive forces between atoms so much energy is needed to separate metals.
Non-metals are mostly held together by covalent bonds between 2 atoms. But between molecules, there are only weak van der Waal forces of attraction.
The boiling point which mainly depends on the intermolecular attraction will be high for metals as they have a high amount of attraction forces between metal atoms whereas there are weak forces of attraction in between gas molecules.
Melting points of solids are high because as temperature decreases the attraction forces increase rapidly compared to non-metals which result in solidification at relatively high temperature.
So, the correct answer is “Option A”.

Note: With an increase in the number of electrons in valence shell metallic bond strengthens resulting in high melting and boiling points. That’s why transition metals have higher melting and boiling points compared to s and p block metals.