Narrative
Description of The Science of Change Poster
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Chemistry is the science of substances - their composition, structure, and properties. "The Science of Change" poster illustrates the dynamics of chemistry, using important relationships to show how substances interact, transform, and change. An understanding of the behavior and characteristics of matter is essential to the ideas covered by the high school chemistry curriculum.
The first section concerns composition: the nature of substances, the origin of elements, their bonding and transformations. An understanding of atomic structure is fundamental for every aspect of chemistry. The atoms of hydrogen, carbon, and oxygen are drawn with some artistic license, as a compromise between Bohr-Rutherford and quantum mechanical models of the atom.
The atoms on the poster are presented in their ground states. Teachers can refer to those models when teaching atomic structure, valency states and bonding, as well as periodicity- H - 0.3A; C - 0.77A; O - 0.66A. Generally, within the main groups of the Periodic Table, the atomic size increases as the number of electron shells increases, while decreasing within each period as more electrons in each shell are strongly attracted by the nucleus. The interacting atoms are depicted as energetic, unstable particles that can form different substances as a result of their collisions. The various possible combinations for bonding lead to millions of existing structures. The colors of the presented atoms correspond to their emissions in a spectroscopic display.
The second section of the poster shows why there are so many structures in nature; atoms of which substances are composed may be united with each other in different ways. Chemists classify substances as elemental forms (containing only one type of atom and unable to be separated by ordinary chemical change), compounds (having two or more different types of atoms and whose structures can be decomposed into simpler ones by chemical change) and mixtures (containing elemental forms and/or compounds, and each constituent part retaining its individual properties).
The third section of the poster concerns properties and application of substances. Generally, we teach students to distinguish between physical, chemical, and biological properties. The process of photosynthesis shows a chemical transformation involving compounds (CO2 and H2O) which produce such life supporting substances as glucose (C6H12O6) and oxygen (O2). Two photos illustrate the reactions involving air: fireworks and carbon monoxide (CO) catalytic conversion; the latter is the most abundant air pollutant.
"The Science of Change" poster visualizes the basic concepts used for the teaching and understanding of chemistry. With the examples of three atoms only - hydrogen, carbon, and oxygen - interacting and forming various substances, the poster contacts almost every part of the high school chemistry curriculum.
Wright Fellow Magdalena Tsavkova was responsible for producing this poster, with art work done mainly by Dana Berry.