Question

A piece of chalk can be broken into small particles by hammering but a piece of iron cannot be broken into a small particle by hammering. Which characteristic of the matter illustrates the observation.

Answer 1

Hint: Since in chalk the particles forces between the chalk particles are not so strong hence they can be easily broken up while the inter-particle force between the particles of iron is strong as there are strong metallic bonds between them. Hence they cannot be easily broken down.

Complete step by step answer:
Intermolecular forces are the forces which mediate interaction between atoms, including forces of attraction or repulsion which act between atoms and other types of neighboring particles, e.g. atoms or ions. Intermolecular forces are weak relative to intramolecular forces – the forces which hold a molecule together. For example, the covalent bond, involving sharing electron pairs between atoms, is much stronger than the forces present between neighboring molecules. Both sets of forces are essential parts of force fields frequently used in molecular mechanics.
Attractive intermolecular forces are categorized into the following types.
-Hydrogen bonding /H-bonding
-Ionic bonding
-Ion–induced dipole forces
-Ion–dipole forces
-van der Waals forces and London dispersion force

A metallic bond is the sharing of many detached electrons between many positive ions, where the electrons act as a "glue" giving the substance a definite structure. It is unlike covalent or ionic bonding. Metals have low ionization energy. Therefore, the valence electrons can be delocalized throughout the metals. Metallic bonds cause many of the traits of metals, such as strength, malleability, ductility, luster, conduction of heat and electricity. Since chalk is an amorphous solid it does not have any particular lattice so the intermolecular force strength decreases, as a result the piece of chalk can be broken into small particles by hammering. On the other hand iron metallic bonds are present which are very strong in nature and give the property of malleability, ductility, luster, conduction of heat and electricity .

Note: Both are solid but are not the same, don’t judge them only on their physical state. Consider their composition and the property of particles.