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Bonding
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Ionic bonds

One of the two more common bonds (the other being covalent) is ionic and it is the formation of
positive and negative ions due to electrons being transferred from one atom to another
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The compounds are held together by electrostatic attractions and the greater these attractions
are the greater amount of energy will be released when the ions join together
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The element will form the ion that provides for the most stability and over all released energy
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Ionic bonding in Sodium Chloride (2015)
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As illustrated in the diagram above, by giving the electron away it would get more stable
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After giving electron away: 2, 8)
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(Chlorine structure: 2, 8, 7
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)
By Sodium giving its electron to Chlorine, both elements will become more stable
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When chlorine gains one electron the imbalance will be 17 protons to 18 electrons and a 1- ion has
been formed
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This is referred to as the octet rule
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Compounds like Sodium chloride exists of an endlessly repeating lattice of ions
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This means that
there could be trillions of Sodium ions and chloride atoms packed together depending on the size of the
crystal
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In ionic bonding, no matter of the direction the bond will always be the same
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(Loudon, 2002 p
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You can easily work out the formula of ionic compounds by writing down the symbols of the
compounds; determine the charge (you can get it from their position on the periodic table e
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Magnesium in the second column will be charged Mg+2), then you calculate how to make the
compounds neutral by finding the lowest common multiple
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

Covalent bonds

Covalent bonds share a pair of valence electrons, when the atoms that are bonded together have a
lower total energy than atoms that are separated they form a covalent bond
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(Atkins, 2014)
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They are also attracted to the nucleus of both
atoms
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The two types of covalent bonding are Polar and non-polar
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2 The linear structure of Carbon dioxide (2015)

Carbon Dioxide (see diagram above) has two polar carbon bonds and two polar oxygen bonds because
of the difference in electronegativity between the carbon and oxygen atoms
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As a result the
carbon dioxide molecule is non-polar
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They share one electron in order to both gain a full outer shell of electrons
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(Docbrownchem, 2015)
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(VIRTUAL CHEMBOOK 2003)
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3 A molecule of hydrogen chloride would be shown like this

What makes compounds containing covalent bonds different from ionic bonds is that they do not
conduct energy, nor do their solutions
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6)
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This is the
principle referring to electrons around the central atom has tendencies to orient themselves as far
apart as possible
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(About
education, 2015)

Fig
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Intermolecular attractions
are not specific to one type of molecule, it occurs between all molecules, though the strength of it varies
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You will find the hydrogen
atom between two significantly electronegative electrons
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g
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The hydrogen atom will have a slight positive charge as a result of the electron

3

affinity
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(Encyclopaedia Britannica, 2015)
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The two strands of the double helix are held together by transpiring
hydrogen bonds between nucleotide base pairs that complements each other
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Fig
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By looking at the Lewis structure of the molecule you can determine what the possibility is for
hydrogen bonding to occur
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There must also be a semi-partial charge
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This lays out a base for hydrogen
bonding to occur
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The shared pair of electrons provides each hydrogen atom with two electrons in its valence shell (the 1s)
orbital
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(VIRTUAL CHEMBOOK 2003)
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(Ritchie, Gent
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60)
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They lack in strength compared to ionic and covalent
bonds and the bonding will be effective when two molecules are closely interactive
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The positive end is attractive to a
negative end and the negative end is attracted to the positive end
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78 The figures show two arrangements of polar iodine monochloride (ICl) molecules that give rise to dipoledipole attractions

In this case chlorine will be the electronegative atom and has the negative charge
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And will be attracted to the negatively
charged chlorine
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Van der Waals forces;

Fig
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This type of bonding is however limited to molecules that has no
other intermolecular forces such as noble gases (Ar, He, Rn etc
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The force’s strength in Van der Waals forces depends on the size of the atoms and molecules, the bigger
size the bigger force
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5

The distinct difference between van der weal forces and dipole-dipole is the symmetry
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References
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Chemguide (2012) IONIC (ELECTROVALENT) BONDING [Online] Available from:
http://www
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co
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html [Accessed: 16th December 2015]
Chemguide (2012) IONIC STRUCTURES [Online] Available from:
http://www
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co
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html [Accessed: 16th December 2016]
G
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Organic chemistry
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Oxford: Oxford universities press
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Wyman (2015) Writing Ionic Compound Formulas: Binary & Polyatomic Compounds [Online]
Available from: http://study
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html [Accessed: 16th December]
Peter W
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britannica
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elmhurst
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html [Accessed 16th December 2015]
Boundless
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boundless
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docbrown
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htm
[Accessed 16th December 2015]
VIRTUAL CHEMBOOK (2003) Covalent compounds [Online] Available from:
http://chemistry
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edu/vchembook/161Ahydrogenbond
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about
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htm [Accessed: 16th December 2015]
Encyclopaedia Britannica (2015) Hydrogen Bonding [Online] Available from:
http://www
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com/science/hydrogen-bonding [Accessed: 16th December 2015]
Paul Arnold (2009) DNA Structure: Hydrogen Bonds [Online] Available from:
http://www
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com/science/genetics/articles/23384
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elmhurst
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html [Accessed 16th December 2015]
Rob Ritchie, Dave Gent (2015)
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Oxford: Oxford university press
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Chempurdue Education (2015) Dipole-Dipole forces [Online] Available from:
https://www
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purdue
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html [Accessed: 16th December 2015]
BBC Bitsize (2014) Intermolecular forces of attraction [Online] Available from:
http://www
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co
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http://devarchive
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org/contents/a1fb5520-d6b1-4d4c-9cb0-59905b04ec12@2/chemical-bondingionic-bonding (2015)
2
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https://www
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com/chemistry/textbooks/boundless-chemistry-textbook/advanced-conceptsof-chemical-bonding-10/molecular-shape-and-polarity-80/dipole-moment-357-6407/ (2015)
http://www
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co
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cnxmlplus (2015)

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4
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8
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weebly
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wikibooks
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ucdavis
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chem
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edu/gchelp/liquids/dipdip
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com/van-der-waals-forces

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