The first secondary-school chemistry textbooks appeared in the second the criteria for assessing the quality of secondary-school chemistry textbooks. PDF | The teaching of chemistry in Serbia as a separate subject dates from The first secondary-school chemistry textbooks appeared in. 𝗣𝗗𝗙 | This study evaluated the Chemistry Textbooks in use in Nigerian performance of the Nigerian secondary school students in chemistry is dwindling.
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The whole range of senior school certificate examination (SSCE) syllabus has been Senior Secondary Chemistry Textbook 2 Lagos Longman Publishers. New School Chemistry By Osei Yaw Ababio Free PDF eBook Download Form Popularity download chemistry textbook for senior secondary school form. Fill Online. Excellent reviews. Form Popularity osei yaw ababio chemistry textbook pdf form. Get, Create, Make and Sign new school chemistry pdf. Fill Online.
However, the caption may not enable the reader to understand the image easily.
The caption is too brief, and neither explicit nor comprehensive. In this case, the reader is left to make sense of the content of the representation. Discussion and implications This study investigated representations of chemical phenomena in chemistry textbooks used in Nigeria.
The overarching aim of the study was to determine the extent to which the representations depicted in chemistry textbooks can facilitate meaningful and conceptual understanding of chemical phenomena.
In relation to types of representations, symbolic representations were dominant. When compared to macroscopic representations, the proportion of symbolic to macroscopic representations in the textbooks was in a ratio 8 : 1. In this regard, chemistry textbooks focus heavily on symbolic levels, most of which are equations, formulas, symbols and mathematical derivations. One concern raised by the dominance of symbolic representations is that learners may be restricted from seeing chemical phenomena at different representational levels.
As a result, students may encounter difficulties in developing conceptual understanding that is fundamental to certain chemical concepts and may experience cognitive overload and a waning motivation to learn chemistry Talanquer, ; Dangur et al. This is consistent with the findings of Nyachwaya and Wood, ; Shehab and BouJaoude, and particularly Gkitzia et al. In terms of dominance, after the symbolic were macroscopic representations.
It is also important to note that, this is not to suggest an emphasis on depiction of representations at the macro level, but that textbook designers should rather make visual or image representations that are abstract, real and observable to students.
The results of Nyachwaya and Wood's study contradicts this finding, with a low indication of macroscopic representations. We assume that what accounts for this difference is that Nyachwaya and Wood evaluated advance physical chemistry textbooks, which predominantly featured symbolic representations.
In addition, the results of our study indicated a very small proportion of sub-microscopic representations in the textbooks and this fail to address the important point that many chemical phenomena are understood at the particulate level Gilbert and Treagust, Having established the critical role played by the sub-microscopic level in helping students develop mental images of intangible concepts, it becomes equally important that textbook authors and publishers give adequate attention to this form of representation.
Similarly, in a study on how visuals that focus on the particulate nature of matter are used in middle school science textbooks, Kapici and Acikalin-Savasci also reported a less frequent use of the sub-microscopic levels in chemical explanations. The use of integrated representations in textbooks, such as the multiple and hybrid were infrequent. While multiple and hybrid representations were the fewest, there was not a single mixed representation.
However, our results indicate a low prevalence of multiple representations, but rather higher prevalence of the discrete levels, which Treagust et al. Given the role played by these representations in aiding conceptual understanding of chemical concepts, it is a cause for concern that authors, and publishers have not responded to the request for substantial integration of sub-microscopic, multiple, hybrid and mixed representations in the textbooks NERDC, The application of the second criterion on relatedness of representations to text content reveals significant findings.
They are significant because, even though, there are representations that were completely related to the text content, the representations were not linked.
Only about This indicates that authors included representations in textbooks without paying sufficient attention to how these representations could best be linked to the text content. The importance of relatedness of text to representations in terms of completeness and linkage is that readers do not have to try to establish a link and interpret the image in relation to the text by themselves Pozzer-Ardenghi and Roth, Once there is a cognitive overload occasioned by partial or unlinked representations, students could become discouraged and eventually shutdown.
It is not impossible that students could also make incorrect interpretations of images that are not related or linked to the text content Kapici and Acikalin-Savasci, The proximity should be such that they are within the same page.
As Wu and Shah suggested, text and the accompanying representations should be presented close together, so that students can easily understand the association between them. The germaneness of image captions in textbooks relates to the explanation these give to the entire representation and the understanding they convey to readers.
Our findings indicated that more than half of the visuals had suitable captions. However, there were also images with problematic captions that did not clearly portray the understanding the visuals were meant to convey.
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The existence of images without captions was minimal. Conclusion The study of chemistry largely involves chemical phenomena that are not open to direct observation. Chemistry as a visual science, therefore, requires the integration of chemical representations to depict these phenomena in textbooks and during classroom instructions, for effective teaching and learning of chemical concepts to take place.
Where the teacher may be limited in portraying these phenomena in two-or three-dimensional representations during instruction, the textbook becomes a vital and indispensable tool for conveying an adequate understanding of the underlying concepts and principles of a chemical phenomenon under investigation.
The overarching goal of this study was to investigate how chemical phenomena are represented in chemistry textbooks, through the types and dominant representations, the relatedness and linkage of images or visuals to the text content and the suitability of captions that link images to texts.
The findings that have emerged from this study, particularly the dominance of symbolic representations over the other representations, the comparatively fewer examples of hybrid and multiple representations; and the non-existence of mixed representations should raise serious concerns for chemistry educators within the geographical context of this study. Our results showed the prevalence of symbolic representations and insufficient integration of two or more levels of chemical representations to depict phenomena.
Salta and Tzougraki, , we can conclude that, students who use these textbooks may experience similar difficulties in trying to make sense of the chemical concepts depicted by symbolic representations. Given that these results are very similar to those of other international studies Gkitzia et al. In this way, teachers who understand the role of chemical representations may also be able to use textbooks to scaffold meaningful learning at each level, particularly at the sub-microscopic level, and then assist students to understand the different levels of chemistry.
It is equally important that curriculum developers and textbook writers affirm these representations in the chemistry curriculum and provide teachers with the necessary support for them to reflect on the representations and emphasize chemical concepts at the different levels in chemistry classes.
For instance, if teachers present the concept of kinetic molecular theory of matter to students and use the combination of macroscopic, sub-microscopic and symbolic representations, students can observe the phenomenon under investigation, develop conceptual understanding from the explanation of the phenomenon, and be able to symbolize the phenomenon effectively.
Teachers should explore other alternative resources such as conceptual models or computer-based 2D or 3D models, and the internet to provide rich experiences for students to develop mental images of intangible phenomena which can foster meaningful understanding of chemistry. Conflicts of interest There are no conflicts of interest to declare.
Appendix 1 Examples of representations for criterion analyzed and coded in this study. The image was used to represent how salt is produce from sea water by evaporation. An example of a sub-microscopic representation taken from New School Chemistry textbook.
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It was used to portray the structure of an atom. An example of a symbolic representation taken Comprehensive Chemistry for Senior Secondary Schools textbook. An example of a hybrid representation taken from New School chemistry textbook. It was used to represent lattice structure of sodium chloride. It depicts the reaction between hydrogen and chlorine gases to form hydrogen chloride gas at symbolic and sub-microscopic levels.
The symbolic and sub-microscopic representations are also placed in parallel so that students can understand their links. The pictures illustrate that as time goes, on the concentration of the solution decreases. Therefore, it is completely related. An example of a representation that is completely related but unlinked.
The image is placed in an experiment and stands right next to the text that explains the experimental procedure. Therefore, it is unlinked. The image is considered to be partially related and unlinked. The accompanying text generally refers to the usefulness of chemistry and the intensive chemistry research that goes into the manufacturing of textile fabrics, building materials, medicine and road construction, without mentioning the names of the chemicals in the laboratory glasswares and what they could be used for.
In addition, the representation is not linked to the text. An example of a representation taken from New School Chemistry textbook that is unrelated to the text. The content text next to the image refers to liquefied petroleum gas which is usually a mixture of propane, butane and other gases, that can be compressed into liquid at relatively low pressures, and consequently piped for both industrial and commerce use.
Therefore, it is unrelated. The caption indicates that alloys of copper can be used to make sculptures and steel are in high demand for building and construction of bridges. An example of a representation with a problematic caption. There are no explicit labels of the internal elements of the ice to show how oxygen and hydrogen atoms form hexagonal symmetry near the tetrahedral bonding angles.
An example of a representation with no caption. Acknowledgements The authors would like to thank Prof. Yvonne Reed, University of Witwatersrand for providing valuable comments and proofreading the manuscript. We equally appreciate the First Africana Publishers for their permission to reuse images from the textbooks sampled for this research.
References Ababio O. Abd-El-Khalick F. Ainsworth S. Each chapter can be downloaded as a separate pdf file; to see which one you need, move your mouse over the image and the title will appear. General Chemistry - a free textbook compiled from the work of various authors. Please see here for details. Maryland This free book in PDF format is a revised and enlarged version of the first edition published in hard-cover format in by Prentice Hall. Mark Kubinec, are of outstanding quality - perhaps the best college-level general chemistry tutorials available..
There are more than of them, organized into 38 lessons; many of the latter contain problem-solving tutorials, interactive quizzes, and lab demonstrations.
Most of the videos are fairly short min and can be accessed in any order. The emphasis is on basic principles of atomic and molecular electronic structure, thermodynamics, acid-base and redox equilibria, chemical kinetics, and catalysis.
More MIT Chemistry lectures and videos.
Yale Freshman Organic Chemistry - Another excellent series, this one covers the two-semester first-year course which includes organic chemistry. These are llive classroom lectures, given by Prof.
Michael McBride. His descriptions of the historical development of important concepts is unusually good, and adds to their understanding.
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Some of the projected slides are hard to read. Each of these contains topics ordinarily included in "general" chemistry, as well as more advanced ones that go beyond first-year college level. General Chemistry Online! It is intended primarily for students in beginning chemistry courses. Virtual Chembook - this nicely-done site by Charles Ophardt of Elmhurst College covers a wide swath of general, organic, and environmental chemistry.
The text material is interesting and well written without attempting to be encyclopedic. General Chemistry Virtual Textbook - a free collection of comprehensive, in-depth treatments of various topics, intended to supplement or replace conventional textbook treatments. It is aimed mainly at the first-year college level, but advanced high school students will find much of it useful. Steve Lower, Simon Fraser University The Chemogenesis Webbook - this extensive, excellent and comprehensive site by Mark Leach tells how chemistry emerges from the Periodic Table and bifurcates into the rich and extraordinary science that we know and experience.
Chemistry tutorial series on YouTube and other video collections - a summary of the major collections, including the Khan Academy, and those done by various teachers, mostly at the high school level. WikiBooks on Chemistry - Many topics in general chemistry are covered here, and are worth looking at.
But as in any "wiki-" type project to which anyone can contribute, the quality is variable, and the visual design is primitive. Tanner's General Chemistry - a large collection of pages on matter including quantum theory , physical chmistry, electrochemistry, and aqueous solutions. Chemistry Web Resources - this site maintained by Ron Rinehart of Monterey Peninsula College contains a wealth of material oriented toward chemical education, all well organized in a visually-attractive way.
ChemPaths: Student Resources for General Chemistry - a comprehensive collection of tutorials from the Chemical Education Digital Library KnowledgeDoor - an excellent compendium of Chemistry- and Science-related data, in many ways more comprehensive than the Handbook of Chemistry and Physics, and certainly more convenient to use. Should be bookmarked by every serious Chemistry student! The ChemCollective student page has links to practice problems and tutorials on various topics.
College physics for students of biology and chemistry - This hypertextbook by Ken Koehler is nicely organized and is the ideal place to go when your Chemistry textbook lets you down. How to pass chemistry - sound advice that is widely ignored.The representation is hybrid in nature and is intended to describe how nitrogen-fixing microorganisms capture atmospheric nitrogen, and convert it to ammonia NH 3 , which can be taken up by plants and used to make organic molecules.
A summary of the block arrangement of elements based on the outermost energy levels for s- and p- block elements; and the orbitals being filled for d- and f- block elements. This text is more comprehensive than many others in terms of acid-base equilibria as the authors do an excellent job of providing examples of quantitative amounts at equilibrium for both weak acids and weak bases the latter is frequently absent. This pressure builds up until the space above the liquid is saturated with vapour.
Three fundamental particles are present in the atom.
The vol nue of gas molecules is negligible compared to the container volume.