Arrangement of elements
Introduced| English | Meaning |
|---|---|
| Periodic Table/ˌpɪərɪˈɒdɪk ˈteɪbl/ | An arrangement of chemical elements by atomic number that displays recurring patterns in their properties. |
| groups/ɡruːps/ | A vertical column in the periodic table whose elements have related outer-electron configurations and chemical properties. |
| periods/ˈpɪərɪədz/ | A horizontal row of the periodic table, corresponding to the principal shell occupied by the outer electrons of its elements. |
| metals/ˈmetlz/ | Elements that typically conduct heat and electricity well and are malleable, with bonding involving delocalised electrons. |
| non-metals/nɒn ˈmetlz/ | Elements that generally lack metallic properties such as high electrical conductivity and malleability. |
| metalloids/ˈmetəlɔɪdz/ | metalloids |
| proton number/ˈprəʊtɒn ˈnʌmbə/ | The number of protons in an atomic nucleus, which identifies its element. |
The chemist's map
- Over a hundred elements could be chaos — but the Periodic Table 周期表 organises them perfectly.
- Its layout reveals patterns in how elements behave.
Elements in the Periodic Table are arranged in order of increasing:
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They are ordered by atomic number.
Rows and columns
- Elements are arranged in order of increasing proton (atomic) number.
- Vertical columns are groups 族; horizontal rows are periods 周期.
The periodic table arranges the elements by atomic number
Elements in the same group have the same number of:
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Same outer electrons → similar properties.
The period number equals the number of electron shells.
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Each period adds a shell.
The vertical columns of the Periodic Table are called ______.
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Groups share outer electrons and properties.
Groups and periods
- Elements in the same group have the same number of outer electrons, so similar properties.
- The period number = the number of electron shells.
Spot a trend across a period
Reading across a period, properties change in a regular, repeating pattern. Switch the trend to watch atomic radius, ionisation energy or melting point change element by element.
In the Periodic Table, metals are found:
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Non-metals are on the right; metals left and centre.
Metals 金属 and non-metals 非金属
- Metals are on the left and centre; non-metals on the right.
- A zig-zag line separates them; metalloids 准金属 sit near the boundary.
Worked example. Sodium and potassium are both in Group I, with one outer electron. That's why they react in very similar ways — the group number tells you the chemistry.
You've got it
- the Periodic Table orders elements by proton number 质子数
- groups (columns) share outer electrons and properties; periods (rows) = number of shells
- metals are left/centre, non-metals right, split by a zig-zag line