Atomic World

Unit Overview

This Unit is a continuation of “Matter and Energy” which facilitates students to further understand scientific concepts related to the microscopic world such as “matter” and “chemical changes and physical changes” as well as learning contents including “solutions”, “acids and alkalis” and “chemical reactions”. Students will conduct various practical activities to learn using physical methods to separate different substances. They will also participate in designing experiments involving the mixing of acids and alkalis, and observe the changes in mass for certain substances before and after combustion. Through these activities, students will be able to distinguish between chemical and physical changes based on observations. During the activities, students will learn about the properties of common acids and bases, using indicators to test the pH of different solutions, and guide them to recognise the potential hazards of handling acids and bases, as well as safety precautions during laboratory operations, thereby fostering a considerate and responsible attitude in students. In addition, students will learn about the relationship between solutes, solvents and solution, and the calculation of concentration of solution, verifying the conservation of mass in the dissolving process through experiments, and investigate the factors that affect the rate of dissolving (e.g. temperature, time of stirring, particle size), which supports students to practice experimenting skills and facilitate them to understand the overarching concept of “change and constancy”. Teachers can also design other appropriate learning and teaching activities to enable students to develop and master the following skills: a) using specific data to induce a general trend, conclusion or model b) making inference to the best possible explanation to the observed phenomenon c) identifying independent variables, dependent variables and control variables d) making qualitative observations and quantitative measurements e) commenting accuracy and precision in a scientific measurement f) setting up a control experiment to avoid confounding factors and identify causation g) using scientific notation, significant figures and ratio for presenting scientific data h) using tables and graphs for data analysis