原子、元素与化合物
Atoms, Elements & Compounds
解释原子、元素和化合物之间的区别；描述简单的玻尔原子模型（原子核内有质子和中子，电子在壳层中）；书写并解读化学符号和简单化学式
Explain the differences between atoms, elements, and compounds; describe the simple Bohr model of the atom (nucleus with protons and neutrons, electrons in shells); and write and interpret chemical symbols and simple formulae
学习证据 / Evidence
- 定义原子、元素和化合物，并通过实例区分它们
- 画出简单的玻尔原子模型，标注原子核（质子/中子）和电子壳层
- 读取化学式，识别其中的元素以及每种原子的数量（例如 H₂O、CO₂、NaCl）
- 识别混合物和化合物之间的区别
- Defines atom, element, and compound and distinguishes between them with examples
- Draws a simple Bohr model of an atom labelling nucleus (protons/neutrons) and electron shells
- Reads a chemical formula to identify the elements and number of each atom (e.g. H₂O, CO₂, NaCl)
- Identifies the difference between a mixture and a compound
评估问题 / Assessment
如果{{name}}在标签上看到公式 H₂O，他们能解释其含义吗——涉及哪些原子、每种原子各有多少个，以及为什么水是化合物而不是氢和氧的简单混合物？
If {{name}} saw the formula H₂O on a label, could they explain what it means — which atoms are involved, how many of each, and why water is a compound rather than just a mixture of hydrogen and oxygen?