Support materials only that illustrate some possible contexts for exploring Science as a Human Endeavour concepts in relation to Science Understanding content.
Development of organic and inorganic nanomaterials is increasingly important to meet a range of contemporary needs, including consumer products, health care, transportation, energy and agriculture (ACSCH013). Nanomaterials have special physical and chemical properties that make them useful for environmentally friendly products, such as more durable materials, dirt- and water-repellent coatings designed to help reduce cleaning efforts, and insulating materials that improve the energy efficiency of buildings (ACSCH015). Although there are many projected environmental benefits, there are also potential risks associated with the use of nanomaterials due to the size of the particles involved (for example, some are able to cross the human blood-brain or placental barrier) and the unknown effects of these particles on human health and the environment (ACSCH013).
There is a large range of situations in chemistry where knowing and communicating the level of purity of substances is extremely important. Impurities can affect the physical and chemical properties of substances, resulting in inefficient or unwanted chemical reactions. Scientists use methods such as mass spectrometry to identify impurities and the level of contamination (ACSCH014). Separation methods which improve the purity of substances are used for food, fuels, cosmetics, medical products and metals used in microelectronic devices. Scientific conventions and international standards are used to represent the purity of materials to ensure consistent applications of standards (ACSCH009).
Carbon is far more prevalent in living organisms than silicon, even though silicon is more abundant than carbon in Earth’s crust. This has caused some scientists to question why life on Earth has evolved to be carbon-based. Although carbon and silicon are found in the same group of the periodic table and share similar characteristics, carbon has a range of properties that mean there is more variety in its interactions and the molecules it can form, which is pivotal to biochemical molecules such as carbohydrates, proteins and DNA. These properties of carbon, in addition to analysis of elements found in meteorites, comets and interstellar clouds, cause many astrobiologists to theorise that if life exists elsewhere in the universe, it will be carbon-based as it is on Earth (ACSCH010). Astrobiology, which is concerned with the distribution of life in our own and other solar systems, is a highly interdisciplinary field that draws on the findings of a range of scientists from areas such as geology, molecular biology, astronomy and chemistry (ACSCH011).