金属および合金：層を歪ませて滑りを抵抗させる
導入済み| English | 意味 |
|---|---|
| alloy/ˈælɔɪ/ | 合金 |
| hardness/ˈhɑːdnəs/ | 硬度 |
What would explain this observation?
- A pure metal’s regular layers can slide when a force is applied. Introducing different-sized atoms can hinder that sliding, helping explain why an alloy 合金 is harder.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- Most metals have high melting and boiling points because their giant structures have strong metallic bonding. Atoms in a pure metal are represented in regular layers, which can move past one another while attraction to delocalised electrons persists. This permits bending and shaping. Pure metals can be too soft for particular uses, so they are mixed with other elements to form alloys.
- alloy: A metallic mixture containing a metal and one or more other elements; hardness 硬度: Resistance of a material to indentation or scratching.
合金为何比其纯金属更硬？
難易度 1/5 · 100 コイン + 今日初回完了時に小ボーナス付与
添加された原子はサイズが異なるため、規則正しい層を歪ませ、層同士の滑りを妨げる。このすべり抵抗が硬度である。新しい元素は生成されず、電子も脱出しない。
各専門用語を正確な意味と対応させよ。
難易度 2/5 · 140 コイン + 今日初回完了時に小ボーナス付与
関連する物理量やプロセスを区別するために定義を使用せよ。
Choose evidence that can test it
- Different-sized atoms distort the regular layers and make sliding more difficult, so many alloys are harder than the corresponding pure metal. Hardness is resistance to indentation or scratching, while strength concerns resisting deformation or failure under a load; do not treat the words as identical measurements. An alloy still has metallic bonding and need not have one fixed compound formula.
- Compare equal-size atom layers with a model containing some larger atoms. Show the disruption and explain its effect rather than merely saying alloy atoms are bigger. Use supplied hardness data and actual teacher-approved samples with suitable tools. Compare the same test method and conditions; an arbitrary harder sample does not establish how every possible alloy behaves.
この場合、調査やモデルをより妥当にする2つの習慣は何か。
難易度 2/5 · 140 コイン + 今日初回完了時に小ボーナス付与
条件や仮定を明記することで他者が正確に再現でき、根拠となる証拠を記録することで結論を検証できます。相反する結果を隠すと、誤った結論を疑う証拠を失いますし、単一の測定でより広い主張を成立させることはできません。
Work from known quantities
- State the known values and their units. Choose the relation because its assumptions fit this case, then rearrange before substitution.
- Known: supplied model hardness values are 40 units for a pure metal and 70 for an alloy measured by the same method. Increase=70−40=30 units; percentage increase=30/40×100=75%. These fictional values quantify one comparison and are not universal values or a complete explanation of the structural cause.
A supplied hardness rises from 50 to 80 units. Calculate the percentage increase. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
suppliedの硬度が50から80単位に上昇しました。百分率増加を計算してください。
難易度 2/5 · 140 コイン + 今日初回完了時に小ボーナス付与
結果は 60 %である。既知: 硬度は 50 から 80 単位へ上昇。増加量 = 30 単位。増加率 = 30/50 × 100 = 60%。これらは特定の比較のためのモデル値であり、普遍定数ではない。
Check the conclusion and its limits
- An alloy is a mixture, not automatically a new compound with fixed proportions. Added atoms hinder sliding without removing all delocalised electrons. A layer model omits real defects and three-dimensional detail, and high melting point is typical rather than universal for metals.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
An alloy must always be a compound with one fixed atom ratio. This claim is false: An alloy is a MIXTURE of metals (or metals with carbon) whose proportions can vary. A compound has a fixed ratio and new bonding; brass is 60-80% copper without ever becoming a compound.
Metals and alloys: distort the layers to resist sliding: Different-sized atoms distort the regular layers and make sliding more difficult, so many alloys are harder than the corresponding pure metal. Hardness is resistance to indentation or scratching, while strength concerns resisting deformation or failure under a load; do not treat the words as identical measurements. An alloy still has metallic bonding and need not have one fixed compound formula.
合金は常に一定の原子比を持つ化合物でなければならない。
難易度 1/5 · 100 コイン + 今日初回完了時に小ボーナス付与
合金は、組成が変化する可能性のある金属（または金属と炭素）の混合物である。化合物は固定比率と新たな結合を持つ。真鍮は 60-80% の銅を含むが、決して化合物にはならない。
金属と1つ以上の他の元素を含む金属混合物：技術用語を記せ。
難易度 1/5 · 100 コイン + 今日初回完了時に小ボーナス付与
alloyとは、金属と1つ以上の他の元素を含む金属混合物を指す。