Why do ionic compounds are hard crystalline solids?

Answer 1

Ionic solids are hard because they are composed of particles in the form of atoms and radicals, which have strong electrical charges, both positive and negative, in comparison to the weaker electric charges that would be associated with co-valent bonds. Oppositely charged particles will attract each other, in accordance with Coulomb's Law, and the stronger the charge, the stronger the attraction, and in an ionic solid, the charges alternate, to maximize attraction. So if the particles of which a substance is composed attract each other strongly, it is harder to separate them, and that's what hardness is.

Answer 2

Excellent question, but, oddly, the answer lies in the opposite concept; i.e. "Why are metallic elements and alloys soft, as compared to ionic elements and compounds, which are always so very hard?" Metallic elements and alloys (compounds, kinda, sorta) are soft because they are held together by Van der Wals forces, rather than ionic bonding. Van der Wals bonding is rather like a cloud of electrons surrounding and investing the element/alloy, rather than the rigid straight-line bonding of ions, as in, for example, table salt; Na-Cl Na-Cl Na-Cl etc, etc, etc... That's part of the reason the metals are malleable, wheras the ionic elements and (true) compounds are friable, have lines of cleavage, crystalline structure, and many different kinds of 'packing' It also explains why ionic compounds and elements are soluble... but... ...I just noticed this 'answer' is beginning to look more like a textbook...(email me if you need more)

Answer 3

Ionic compounds intra molecular forces deal with charges which dictates their attractions. Example Na+ and Cl- balance out to form NaCl ( include states in a real equation). While their inter molecular forces, which are the forces between molecules causes them to be set up in a crystal lattice structure formation. The molecules line themselves up in a cube compact shape so negative and positive charges are aligned with one another. This causes ionic compounds to all be solid or as you stated "hard". For more reference I recommend you Google the image of a crystal lattice structure to get a better visual grasp of the concept

Answer 4

Ionic compounds are made up of strong electrovalent bond formed by transfer of electrons where basic and acidic radicals are being strongly bound. This results in close packing of the lattice and thus produces hard solid. eg. NaCl

Answer 5

the cations and anions loched tightly into place because of their opposite charge as a result it is difficult to move the ions and the compound is very hard.

Answer 6

the ions are repeated uniformly throughout the compound, it also has a 3 dimensional structure and the valence electrons are out regularly on the valence shel

Answer 7

Ionic compounds form ionic lattices which give rise to crystalline forms.

Answer 8

because the ionic bonds usually form ionic compounds which is salts with strong electric attraction between anions and cations