What is chemistry? (Part 1)

Frost, in ‘Learning to Teach Science’ had made an attempt to describe Chemistry, stating that “Chemistry is about two stories:

The macroscopic world of bulk materials and the invisible world of atoms and molecules.” 

When talking about Chemistry there is always a transfer of information from both sides and when summarised, Frost said:

"It is the story of the flow of energy that accompanies chemical change that links the two.”

Chemistry is seen as the one of the ‘big three’ of the sciences (Wellington & co.) Chemistry fits neatly between the macro world of biology and the largely micro world of physics and in a sense, they both depend upon Chemistry (Stacey Bretz, 2008, p.15). 

Bretz an editor of “Chemistry in the National Science” had been quite determined to make it clear that physics and biology would not be able to function without the ‘world of chemistry.’ She had gone on to say that its language provides the products that people use and that can directly have an influence on everyday lives.

Basic chemical reactions

 Who says chemistry needs to be complicated?

Reactions can be very basic, in fact cooking an egg is an example of a chemical reaction, these reactions are seen as non-reversible. The properties at an atomic level have change and thus meaning that it cannot change back into the structures the atoms had previously. Another good example would be a firework, the rapid oxidation is an example of a chemical change.



Then there is the example of a physical change, this is an example of where something can be reversed. A good common example that I use in my classes is the changing of water into ice and vice versa. The structure of H20 molecules are kept the same (untouched) and thus can easily change states. 

So to summarize, there are two types of reactions:

Chemical reactions - irreversible, for example fireworks or frying an egg

Physical Changes- Reversible, for example Melting ice.