THE A'LEVEL VIEW OF IONIC BONDING
  • Electrons are transferred from one atom to another resulting in the formation of positive and negative ions.
  • The electrostatic attractions between the positive and negative ions hold the compound together.
So what's new? At heart - nothing. What needs modifying is the view that there is something magic about noble gas structures. There are far more ions which don't have noble gas structures than there are which do.
Some common ions which don't have noble gas structures
You may have come across some of the following ions in a basic course like GCSE. They are all perfectly stable , but not one of them has a noble gas structure.
Fe3+[Ar]3d5
Cu2+[Ar]3d9
Zn2+[Ar]3d10
Ag+[Kr]4d10
Pb2+[Xe]4f145d106s2
Noble gases (apart from helium) have an outer electronic structure ns2np6.

Comments

Post a Comment

Popular posts from this blog

A chemical bond is an attraction between atoms that allows the formation of chemical substances that contain two or more atoms. The bond is caused by the electrostatic force of attraction between opposite charges, either between electrons and nuclei , or as the result of a dipole attraction. The strength of chemical bonds varies considerably; there are "strong bonds" such as covalent or ionic bonds and "weak bonds" such as dipole–dipole interactions , the London dispersion force and hydrogen bonding .
Read more
Image
Boron trifluoride, BF 3 A boron atom only has 3 electrons in its outer level, and there is no possibility of it reaching a noble gas structure by simple sharing of electrons. Is this a problem? No. The boron has formed the maximum number of bonds that it can in the circumstances, and this is a perfectly valid structure. Energy is released whenever a covalent bond is formed. Because energy is being lost from the system, it becomes more stable after every covalent bond is made. It follows, therefore, that an atom will tend to make as many covalent bonds as possible. In the case of boron in BF 3 , three bonds is the maximum possible because boron only has 3 electrons to share
Read more
Metallic bonding constitutes the electrostatic attractive forces between the delocalized electrons , called conduction electrons , gathered in an electron cloud and the positively charged metal ions. Understood as the sharing of "free" electrons among a lattice of positively charged ions ( cations ), metallic bonding is sometimes compared with that of molten salts ; however, this simplistic view [ which? ] holds true for very few [ which? ] metals . In a more quantum-mechanical view, the conduction electrons divide their density equally over all atoms that function as neutral (non-charged) entities. [ citation needed ] Metallic bonding accounts for many physical properties of metals, such as strength , ductility , thermal and electrical conductivity , opacity , and luster . [ 1 ] [ 2 ] [ 3 ] [ 4 ] Although the term "metallic bond" is often used in contrast to the term " covalent bond ", it is preferable [ by whom? ] to use the term metallic bon...
Read more