STEM stands for the grouping of the first letters of Science, Technology, Engineering and Mathematics. Starting 2016, HK Education Bureau launched a scheme for promoting STEM education in both primary and secondary schools. In short, it aims to strengthen students’ ability to integrate and apply knowledge and skills across different STEM disciplines. Through the promotion of STEM education in schools, the Bureau aims to enhance and sustain the competitiveness of Hong Kong.
Creativity dependents heavily on sustainable and challenging thinking but bringing it to practice is not a must. On the contrary, innovation involve technical skills to transform creative ideas into brand-new prototypes. Proposed programs (1) and (2) are based on the framework of the DSE Chemistry Syllabus Chapter 4 (edb.gov.hk). They include a series of innovative designs together with related manual and electronic techniques to enable the creative concepts to work at practical level.
Programs (1) and (2) can be used as chemistry curriculum STEM enrichment for teachers and students
STEM achievement is a kind of double-edged sword. It has advantages as well as disadvantages. Like the invention of internal combustion engine in the 19th century, the derived developments enabled fast communications and transportations. At the same time, extensive domestic and industrial usages resulted in energy shortage, all sorts of severe pollutions and extreme climate change. Likewise, Nobel Prize winning Ziegler-Natta catalyst made stunning production of man-made plastics possible. The readily available and decompostion-resistant nature of this kind of materials not only improved our living quality but more sadly is its accumulated years of use gives rise to disastrous environmental problems, affecting all living things on the Earth. STEM achievements as of now should be sustainable and seen as a holistic development of both human being and nature.
Program (2) Innovative Designs of Micro-scale Chemistry Instrument
The objective of promoting STEM education is to unlash and develop students’ innovative potentials. Innovation is multi-element oriented, cannot be represented by a single discipline or skill. Along with this line of thinking, curriculum related STEM activities should cover a broad spectrum of skills. Micro-scale chemistry experiments appeared to be one of the most innovative science subject reforms in the past years. It can also be regarded as the STEM development of the subject. It not only preserves the traditional elements of study aspects but also injects innovative ideas.
Local chemistry equipment suppliers provide some micro-scale chemistry equipment kits, but not all are suitable for the DSE Syllabus. After years of practical experiences, the author had designed a series of school level innovative qualitative and quantitative micro-scale chemistry instruments for experimentation, imparting a totally new and incentive experience out of traditional practice.
Suggested qualitative and quantitative instruments of the program can all be home made by assembling purchasable parts. Innovative instruments include (not all): (i) Micro-scale Water-less Distillation Set which collects nascent distillate by in situ condensation. The design greatly reduces distillate loss due to time spent on passing a water condenser; (ii) Micro-scale 8-well reaction strip which employs the “Shake-down” and the “1248” techniques for extremely fast kinetic order determination of the “iodine clock reaction”; (iii) Mini heater for activation energy determination of the “iodine clock reaction” which facilitates elucidation of the complete quantitative investigation of dependence of rate on concentration and temperature and hence the derivation of an empirical rate equation; (iv) Micro-scale Relative Molecular Mass (RMM) Kit for an ultra-fast determination of the Gas Constant at r.t.p. or the relative molecular mass of butane gas; (v) Reaction Disc which handles investigations of chemical properties of poisonous gases such as chlorine, ammonia and sulphur dioxide in a very safe manner; (vi) Meltometer for speedy melting point determinations of solid organic derivatives; (vii) Flour Explosion Kit for enhancing students’ awareness of extreme fast oxidation (explosion) resulting from an increase in surface area of reacting particles (powder form) in the presence of air. The fatal 2015 “Colour Powder Party” explosion at Taipei-park and the 2018 “Birthday Celebration” dust explosion injuries at B.U.H.K. could be avoided had people were educated about the deadly chemical reaction consequences of such activities.
The series of innovative micro-scale chemistry instruments offer traditional experiments brand-new experiences. Advantages include: simple operation, small amount of reactant required (normally only one-tenth of traditional amount), safe, time-saving, meets stoichiometric requirements, arouse curiosity, induces motivation for experimentation, enhances environmental conservation and “Green” awareness.
Facing electronic instrument panels with various displays, a lot of students feel the situation threatening, especially eyeing on advanced instruments with unfamiliar display units. Although simple school electronic chemistry equipment such as pH meter, conductance meter and colorimeter are used, they all require calibration procedures and demand understanding of units like Absorbance andμS/cm. This means time would be spent on pre-lab briefing and teachers cannot take it for granted that students could start operating these instruments once given.
In view of these embarrassing situations, and base on criteria of (i) simple operation, (ii) instrument manipulation with no knowledge of display units and (iii) no sacrifice of sensitivity and reproducibility, the author designed a series of electronic instruments based on the “DMM Display Technique” in which a single commercial DMM (digital multimeter, a very inexpensive, versatile and readily available domestic style electrical instrument which should fare for decades to come) acts as the only display unit for different experiments, including those required by the DSE Chemistry Syllabus. Digital display numbers 0 and 100 stands for zero and full-scale measurements, achieving a unit-free situation. Numerical pH display as usual, but units such as absorbance andμS/cm can do away with. The design gears fully to the feature of “simple and user-friendly”. A self-designed electronic sensor is required to install between the probe and the DMM as shown below. Sensor design needs the electronic skills mentioned in Program (1).
(Fig. 1) Set up employing “DMM Display Technique”
Participants make use of the handraft and electronic skills acquired in Program (1) to construct the various probes and sensors. What they all need is to purchase a DMM and are ready for quantitative measurements with suitable constructed probes and sensors. One merit of such homemade activity is participants understand fully the working principles of the instrument. Maintenance is not a problem.
Topic 7 “Postscript” is added to the program. It includes a foreseeable prediction of future STEM achievements stemmed from author’s personal imagination plus information from the internet. Owing to the invention of electricity 200 years ago which laid the foundation of our modern age, followed by the discovery of new materials and rapid development of digital technologies, today is the “Age of electrical power”. No one dare to imagine what the world would look like without electricity. What will a “post-electricity world” look like? Will it come into being at what time?