Molecules分子 · 水
H₂O · bent geometry
CAMBRIDGE IGCSE CHEMISTRY · 0620
Small steps.
Strong understanding.
每一小步，都让理解更扎实。You do not have to understand everything at once. Explore an idea, try a question and build on what you know.不必一次弄懂所有内容。探索一个概念，尝试一道题，在已有知识上继续前进。
18 chapters18 个章节Learn · Practise · Explore学习 · 练习 · 探索
CHEMISTRY IN MOTION看见微观世界
Structures结构 · 离子晶格
Alternating ions
Movement运动 · 扩散
From concentrated to spread out
Schematic models · sizes and motion are illustrative.示意模型 · 大小与运动仅用于直观展示。
Where will you begin?今天，从哪里开始？
01
Learn a topic学习一个主题
Open the chapter menu. Find the ideas you are learning in class.打开左侧章节目录，找到课堂正在学习的内容。
02Practise questions尝试练习
Test your understanding and learn from your mistakes.检验理解，从错误中找到下一步。
03Explore chemistry探索化学
Change a variable. Observe what happens. Ask why.改变一个变量，观察变化，再问一句“为什么”。
A QUESTION TO SPARK YOUR THINKING
Why can you smell perfume
across a room?为什么在房间另一头，也能闻到香水？
Think about what happens to the particles after perfume evaporates.想一想：香水蒸发后，粒子会怎样运动？
Reveal the explanation查看解释
Perfume particles move randomly and mix with air. Diffusion produces net movement from higher to lower concentration. Air currents can also carry the smell.香水粒子随机运动，与空气混合。扩散使粒子整体从高浓度区域向低浓度区域移动；空气流动也会带走气味。
Explore particles and evidence学习粒子与证据Try first. Hints are here to help.先尝试，提示会帮助你。
A wrong answer can show you exactly what to revisit. Progress comes from understanding, not rushing.答错能帮助你发现需要回顾的内容。进步来自理解，不必急着赶进度。