2.2.1/2.2.2 Electron structure, and bonding and structure GapFill

The electrons in an atom sit in energy levels called   stratarungsplanesshells. Each of these has a principal quantum number, denoted by the letter   lsnm. The region of space in which an electron can exist is defined by the type of atomic  contourquadrantorbitalorbit it is in, which will have a characteristic shape. As well as varying in shape, the different types also vary in energy, in the following order:   p<d<ss<p<dd<p<sp<s<d.

One type of chemical bonding involves the sharing of electrons between two atoms; this is  courantchordatecovariantcovalent bonding. When both of the shared electrons in the bond come from the same atom, it is called a coordinate or  vocativegenitiveablativedative bond, and is represented by an arrow. The strength of a covalent bond is measured by its average bond  entropyisotropyenthalpysynergy. The tendency of an atom of an element to draw the electrons in a shared bond towards itself is called its   electronegativityelectroactivityelectropositivityelectrodirectivity. If the value is very different for the two atoms in a bond, there will be an uneven distribution of electron density, and the bond is said to be   molarpolarfocalradial.

All covalent molecules experience at least one type of intermolecular interaction: induced dipole-dipole interactions, also known as   BelfastCardiffLondonGlasgow dispersion forces. Another type, hydrogen bonding, occurs only in molecules with a hydrogen atom bonded to a nitrogen, oxygen or   fluorinesiliconchlorinebromine atom. 

In ionic bonding, there is electrostatic attraction between oppositely charged ions arranged in a giant, regular structure called   a latticea matrixan edificea vector.