元素周期表
The Periodic Table
描述元素周期表如何按周期（横行）和族（纵列）排列，说明门捷列夫的贡献，并利用元素周期表识别金属、非金属，以及预测反应活性的规律。
Describe the organisation of the periodic table into periods and groups, explain the contribution of Mendeleev, and use the table to identify metals, non-metals, and predict patterns in reactivity
学习证据 / Evidence
- 解释元素周期表为什么按周期（横行）和族（纵列）排列
- 说明同一族的元素具有相似的化学性质
- 能在元素周期表中找出金属、非金属和类金属
- 解释门捷列夫如何按原子量排列元素，并预言了尚未发现的元素
- Explains why the periodic table is arranged into periods (rows) and groups (columns)
- States that elements in the same group have similar chemical properties
- Locates metals, non-metals, and metalloids in the periodic table
- Explains how Mendeleev ordered elements by atomic weight and predicted missing elements
评估问题 / Assessment
如果{{name}}正在看元素周期表，他能解释为什么同一列的元素会有相似的性质，并说明门捷列夫做了什么使元素周期表对化学家如此有用吗？
If {{name}} was looking at a periodic table, could they explain why elements in the same column tend to behave similarly — and say what Mendeleev did that made it so useful to chemists?