Textbook of Chemistry for Class IX by Dr. N. K. Sharma, published by Macmillan Publishers India Pvt. Ltd. Revised edition 2017. ISBN: 978-9350374086. Intended for educational and learning purposes, ensuring contents do not violate copyright or intellectual property rights.
This textbook conforms with the Science Curriculum Framework of Bhutan's Ministry of Education, emphasizing 'learning without burden' and presenting science as a dynamic body of knowledge. It promotes hands-on, inquiry-based pedagogy, with examples relatable to a child’s experience.
Key challenges in science learning include rote learning and limited experimentation opportunities. The book aims to foster rational, meaningful learning through experience and verification.
A chapter on 'Introduction to Chemistry' bridges the gap for students transitioning from integrated science to specialized science after class VIII. The textbook includes competency-based questions, topic-end questions, solved examples, and a model question paper.
The book integrates 21st-century skills through active learning strategies and self-assessment opportunities. It welcomes feedback for subsequent editions.
Acknowledgment to individuals for contributions, suggestions, feedbacks and comments in making of the textbook, including Wangpo Tenzin, Curriculum Specialist, and Surjay Lepcha, Curriculum Developer, REC, Paro. Gratitude also goes to teachers who attended the review works at Gelephu in 2014.
Syllabus includes:
Material and their Properties:
Classifying Materials including bonding (metallic, ionic, covalent), duplet and octet rules, formation of ions, giant ionic lattices, simple molecular structures, and giant structures. Physical properties are outlined and compared.
Materials and Change involving organic chemistry. Hydrocarbons (alkanes, alkenes, and alkynes) are explained with general formulas (C<em>nH</em>2n+2, C<em>nH</em>2n, C<em>nH</em>2n−2), IUPAC nomenclature, structural isomers (e.g., hexane), and combustion reactions. Identification of saturated/unsaturated hydrocarbons using bromine water or acidified potassium manganate (VII) is covered. it also touches on petroleum, fractional distillation, cracking, and addition polymers (e.g., polyethene, PVC).
Metallurgy including reactions of metals (Ca, Mg, Zn, Fe, Pb, Cu) with acids, oxygen, and water, reactivity series construction, and prediction of reactions.
Green Chemistry including the nitrogen cycle (importance of converting nitrogen to ammonia, manufacturing of nitrogenous fertilizers, and environmental consequences), carbon cycle and global climate change (role of carbon cycle, burning of fossil fuels), and problems of plastics (environmental hazards, measures to prevent hazards like biodegradable plastics and removal of toxic products from halogenated plastics).
Patterns in Chemistry:
Periodic Table organization (ascending atomic number), connection between outer electrons and element position (group prediction), similar properties within groups with justifications, and periodic properties variations.
Group 1 (Alkali Metals - Li, Na, K) including physical properties, reactions with water, oxygen, and chlorine with balanced chemical equations, trends in reactivity down the group, and prediction of reactions for Cs and Fr.
Group 18 (Noble Gases) encompassing physical properties, changes in properties down the group, and uses based on properties.
Chemical reactions, Conservation of Mass and Stoichiometry including balanced symbol equations.
Rates of Reaction including temperature and concentration alterations, surface area variation, and catalyst addition.
Energy Transfer in Reactions including exothermic and endothermic reaction classification.
Assessment in science measures achievement in knowledge, skills, and attitude. It informs teaching, helps students set goals, assigns grades, and motivates students. Assessment focuses on scientific knowledge, working scientifically, and scientific values/attitudes.
Assessment process involves specific outcomes, clear criteria, varied strategies, descriptive feedback, and student self-reflection.
Scheme of Assessment includes Continuous Formative Assessment (CFA) for feedback, Continuous Summative Assessment (CSA) for grading, and Summative Assessment (SA) at term ends.
Continuous Formative Assessment (CFA):
A continuous process to assess student problems and learning needs, and to identify remedial measures to improve learning.
Techniques: Quiz and debate, class presentation, homework, class work, immediate interaction with students.
Tools: Q&A, checklists and anecdotal records, maintained for each topic throughout the academic year.
Continuous Summative Assessment (CSA):
Grading student's performance and achievements with teacher's feedback.
Students understand what teaching methods and materials work best.
Techniques: Immediate interaction with students, class work, home work, experiments, exhibition, case studies. Observation of student's conduct in group work, field trip, excursion.
Tools: Checklists and anecdotal records, Rubrics (homework, chapter-end test), Practical work rubrics, Project work rubrics.
Summative Assessment (SA):
Assessment conducted at the end of the first term and the end of the year to determine the level of learning outcomes achieved by students.
Techniques: Term examinations - first term and examinations. Home work and chapter end tests, Practical work, Project Work.
Tools: Paper and pencil tests. Checklists and anecdotal records.
Assessment techniques include observation checklists to record student performance, anecdotal notes for specific behaviors, project work for practical application of skills.
Project Work:
Project work helps practice the application of scientific concepts and skills, through exploration and extending scientific understanding. Project work also helps with scientific techniques and skills including, data collection, analysis, experimentation, interpretation, evaluation and drawing conclusion.
Key scientific skills for planning, designing and making scientific artefacts will be learned.
Teachers can help by suggestion project ideals, encouraging creativity, providing a clear set of guidelines for completing project, helping students locate sources of information, presenting their finished projects to the class.
Select a topic for the science project.
Gather background information.
Write the research hypothesis.
Identify variables.
Design an experiment or observation method.
Write a list of material.
Write experiment results.
Write a summary of the results.
Draw conclusions.
The report should start with an introduction on the topic, literature review, methods used, findings, and end with a conclusion. Also show your thanks to those who supported your work. And finally, add references used. Such information should include, the form of document, name of writer, publisher, and the year of publication.
Practical work is integral to thinking and working scientifically, developing understanding, interacting with apparatus and objects.
Assured through rubrics (scored out of 16, reduced to 5% for two terms) and moderation.
Chapter-wise weighting and time allocation is given, with a total time requirement of 4860 minutes for all topics.
Topics covered include Periodic Table, Chemical Bonding, Reactivity of Metals, Chemical Reactions, Conservation of Mass and Stoichiometry, Rate of Reaction and Energy Transfer, Green Chemistry, and Organic Chemistry: Hydrocarbons.
Chemistry studies the properties, composition, and transformation of matter, dealing with material formation, attributes, transformations, and energy exchange. It is the science of atoms and molecules, applicable from elemental level to complex structures. A qualification in chemistry leads to careers inside (washing glassware) and outside the lab (finance and public relations).
Organic chemistry studies structures, properties, and preparation of carbon and hydrogen compounds, overlapping with medicinal, organometallic, polymer, physical organic, and stereochemistry. Inorganic chemistry studies properties and behavior of inorganic compounds (except organic compounds), including crystal structures, minerals, metals, catalysts, and most elements in the periodic table, branching into bioinorganic, geochemistry, nuclear, organometallic, and solid-state chemistry. Analytical chemistry quantitatively and qualitatively determines chemical compounds, used in forensic, environmental, and drug testing. Physical chemistry connects structure to physical properties, studying reaction rates, molecule-radiation interaction, and structures, including photochemistry, surface chemistry, chemical kinetics, quantum chemistry, and spectroscopy. Biochemistry studies biological processes in chemical terms, spanning molecular biology, genetics, pharmacology, clinical biochemistry, and agricultural biochemistry.
The methodology of chemistry involves synthesis through chemical reactions, optimized for yield and purity, typically using literature methods or methodology research. Industries focused especially on polymers and pharmaceuticals involve these applications.
Chemistry has led to advancements in chemical fertilizers, crop protection, food preservation, adulterant testing, cancer therapy, AIDS treatment (AZT), surgical operations (anesthetics), health (synthetic vitamins), superconducting ceramics, and eco-friendly refrigerants.
The periodic table organizes elements by ascending atomic number, with elements in the same group sharing similar properties. The table includes periods (horizontal rows) and groups (vertical columns).
Mendeleev's periodic table was based on atomic weights, while the modern periodic table is based on atomic numbers, as arranged by Henry Moseley.
Periodic trends include valence electron patterns, atomic size variations, metallic character, atomic volume, ionization enthalpy, electron affinity, and electronegativity. These trends exhibit periodicity, repeating after regular intervals.
Group 1 elements (alkali metals) have one valence electron. Group 18 elements (noble gases) are generally inert due to their stable electron configurations, with a few exceptions like xenon forming compounds with fluorine or oxygen.
Assessment involves specific outcomes, shared criteria, varied strategies, feedback, and insight to modify instruction, using observation checklists, anecdotal notes, and project work.
Chemical bonding involves the combination of the atoms through the arrangement and sharing of valence electrons, in attempt to attain a state of stability (duplet or octet rule).
Duplet rule applies to elements like hydrogen and lithium achieving stability with two electrons in their outermost shell.
Octet rule states that atoms gain, lose, or share electrons to achieve a stable configuration of eight electrons in their valence shells.
Types of chemical bonds: electrovalent (ionic), covalent, and coordinate bonds.
Electrovalent (ionic) bonds occur through electron transfer, forming cations and anions held by electrostatic forces, resulting in ionic compounds with specific properties.
Covalent bonds involve mutual sharing of electrons where substances which have covalent bonding can be elements or compounds that form simple molecular structures or giant structures.
Properties of ionic compounds include existing as solids, with water solubility, and high melting and boiling points. Also, ionic compounds are better electrical conductors in solution or in the molten state and are highly brittle.
Coordinate bonds involve sharing of electrons, with the shared pair contributed by one atom (donor) to another without a full octet (acceptor), and are represented by an arrow.
Crystalline solids are classified into molecular (non-polar or polar), ionic, covalent or network, and metallic solids, each with characteristic interparticle forces and properties.
Modern periodic law states that the physical and chemical properties of elements depend on atomic numbers.
Practical works help students to understand the methods by which the scientific knowledge is constructed
Metallic Character or Electropositive Character is the ability of an atom of an element losing electron and form positive ion.