Burning and Bonding

A Year 11 module from the Salters’ Key Stage Four double award gcse science course. This module draws together ideas about chemical bonding and the energy changes associated with bond making and bond breaking. The relationship between type of bonding and the properties of the resulting compounds is considered. The number and type of bonds formed by atoms of different elements is used to establish the relationship between the Periodic Table and atomic structure.

Students’ current knowledge of atomic structure and bonding is reviewed. Covalent bonding in hydrocarbons is considered. The allotropes of carbon are described and there is a text exercise on fullerenes. Ionic bonding is introduced through corrosion of metals. The halogens as a family of elements are introduced through experiments on chemical processes in black and white photography. Properties and uses of halogens and their compounds are reviewed.

The Periodic Table is introduced and its usefulness is illustrated through the typical properties of group I and group II metals, transition metals, halogens and the noble gases.

Section 1: Burning
Molecular models for hydrocarbons, and experiments on burning introduce ideas about energy changes during bond making and bond breaking. There is a brief text exercise on isomers. The idea of activation energy is introduced and the flash points of some fuels may be demonstrated. Consideration of incomplete combustion leads to text exercises on atmospheric pollution from internal combustion engines and the function of catalytic converters.

Section 2: Bonding
Students’ current knowledge of atomic structure and bonding is reviewed. Covalent bonding in hydrocarbons is considered. The allotropes of carbon are described and there is a text exercise on fullerenes. Ionic bonding is introduced through corrosion of metals.

Section 3: A chemical family: the halogens
The halogens as a family of elements are introduced through experiments on chemical processes in black and white photography. Properties and uses of halogens and their compounds are reviewed.

Section 4: Piecing together the jigsaw
Students explore different ways of arranging the elements to bring out patterns in their behaviour. The Periodic Table is introduced and its usefulness is illustrated through the typical properties of group I and groupie metals, transition metals, halogens and the noble gases.

Pages from the 2nd edition Year Ten teacher/technician pack are included at end of Section 4: pp 181 - 186.