Периодические позиции следуют за числом протонов и электронной структурой
Введено| English | Значение |
|---|---|
| group/ɡruːp/ | Группа |
| period/ˈpɪərɪəd/ | период |
What would explain this observation?
- Lithium and sodium are separated by several elements in proton-number order but sit in the same column. Their shared outer-electron pattern explains why their reactions resemble one another.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- The modern periodic table arranges elements by increasing atomic number. A group 族 is a column containing elements with similar chemical properties; a period 周期 is a row. For the main-group first twenty elements, occupied shells give the period, while outer electrons explain group similarities. Magnesium, 2,8,2, is in period 3 and Group 2; chlorine, 2,8,7, is in period 3 and Group 7. AQA uses Group 0 for noble gases, whose outer shell is full.
- group: A vertical column of elements with related chemical properties in the periodic table; period: A horizontal row of elements in the periodic table.
К какой группе AQA относится элемент-представитель главной подгруппы 2,8,7?
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Период равен числу занятых оболочек (3 оболочек: период 3), а группа AQA — числу валентных электронов (7 внешних электронов: группа 7). Эти данные не определяются в обратном порядке.
Сопоставьте каждый технический термин с его точным определением.
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Используйте определения для различения смежных величин и процессов.
Choose evidence that can test it
- Group 1 atoms tend to lose one outer electron and form +1 ions; Group 7 atoms can gain one to form −1 ions. Predict similar reaction types within a group, then use the group-specific trend for relative reactivity. Helium has two outer electrons in a full first shell and belongs with Group 0, not Group 2. Hydrogen is an unusual non-metal and should not be described as an alkali metal simply from its printed position.
- Use the supplied periodic table and numerical structures rather than memorizing an outline alone. Find Z, write the arrangement, count occupied shells, identify the outer count and compare the known group. State a prediction and the evidence for it. These main-group rules do not supply a complete electron-configuration treatment of transition metals.
Какие две привычки делают расследование или модель в данном случае более обоснованными?
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Указание условий и допущений позволяет другим точно воспроизвести работу, а фиксация подтверждающих данных даёт возможность проверить вывод. Сокрытие противоречащих результатов устраняет доказательства, способные оспорить ошибочный вывод, а одно измерение никогда не может обосновать более широкий claim.
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: an unknown neutral atom has structure 2,8,8,1. Its electron total is 19, so Z=19 identifies potassium. Four occupied shells give period 4, and one outer electron gives Group 1. It is predicted to form K⁺ and to react more vigorously with water than sodium under comparable conditions, following the Group 1 trend.
How many occupied shells does a neutral atom with structure 2,8,8,1 have? Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
Сколько занятых оболочек имеет нейтральный атом со структурой 2,8,8,1?
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Результат: 4 оболочек. Дано: конфигурация 2,8,8,1. Число занятых оболочек = 4 (четыре числа в последовательности). Атом находится в периоде 4, а наличие одного внешнего электрона относит его к группе 1.
Check the conclusion and its limits
- A group is vertical and a period horizontal. Similar properties do not mean identical reaction rates. Outer-shell count is not always the printed modern 1–18 group number, and the simplified first-twenty rule must not be applied indiscriminately to every column.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
Elements in the same period must have the same outer-electron count. This claim is false: Across a period the outer shell fills from 1 to 8 electrons, so elements in the same period have every possible outer-electron count. Shared outer count defines a GROUP, not a period.
Periodic positions follow proton number and electron structure: Group 1 atoms tend to lose one outer electron and form +1 ions; Group 7 atoms can gain one to form −1 ions. Predict similar reaction types within a group, then use the group-specific trend for relative reactivity. Helium has two outer electrons in a full first shell and belongs with Group 0, not Group 2. Hydrogen is an unusual non-metal and should not be described as an alkali metal simply from its printed position.
Элементы одного периода должны иметь одинаковое количество внешних электронов.
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В пределах периода внешняя оболочка заполняется от 1 до 8 электронов, поэтому элементы одного периода охватывают все возможные числа валентных электронов. Совпадение числа внешних электронов определяет ГРУППУ, а не период.
Вертикальный столбец элементов со схожими химическими свойствами в периодической таблице: запишите технический термин.
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Группа означает вертикальный столбец элементов со схожими химическими свойствами в периодической таблице.