Difference between revisions of "Period (Chemistry)"
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==Key Stage 3== | ==Key Stage 3== | ||
===Meaning=== | ===Meaning=== | ||
| − | A | + | A '''period''' is a row on the [[Periodic Table]] whose [[element]]s all have the same number of [[Electron Shell]]s. |
===About Periods=== | ===About Periods=== | ||
| − | : [[Atomic Number]] increases as you move along a | + | : [[Atomic Number]] increases as you move along a '''period'''. |
{| class="wikitable" | {| class="wikitable" | ||
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| style="height:20px; width:300px; text-align:center;" |There is a trend in the [[Melting Point]]s as you move along the [[Period (Chemistry)|period]]. | | style="height:20px; width:300px; text-align:center;" |There is a trend in the [[Melting Point]]s as you move along the [[Period (Chemistry)|period]]. | ||
| style="height:20px; width:300px; text-align:center;" |A similar trend can be seen in the next [[Period (Chemistry)|period]]. | | style="height:20px; width:300px; text-align:center;" |A similar trend can be seen in the next [[Period (Chemistry)|period]]. | ||
| + | |} | ||
| + | |||
| + | ==Key Stage 4== | ||
| + | ===Meaning=== | ||
| + | A '''period''' is a row on the [[Periodic Table]] whose [[element]]s all have the same number of [[Electron Shell]]s. | ||
| + | |||
| + | ===About Periods=== | ||
| + | : [[Atomic Number]] increases as you move along a '''period'''. | ||
| + | : The number of the '''period''' is the same as the number of [[Electron Shell|electron shells]]. | ||
| + | |||
| + | ====Trends within Periods==== | ||
| + | {| class="wikitable" | ||
| + | |- | ||
| + | |[[File:Period2ElectronShells.png|center|600px]] | ||
| + | |- | ||
| + | |[[File:Period2ElectronShielding.png|center|600px]] | ||
| + | |- | ||
| + | | style="height:20px; width:600px; text-align:left;" |For the first 3 [[element]]s [[Lithium]], [[Beryllium]] and [[Boron]] all lose [[electron]]s in [[Chemical Reaction|chemical reactions]]. | ||
| + | |||
| + | The [[reactivity]] decreases as you go across the [[Period (Chemistry)|period]] because: | ||
| + | *The outer [[electron]]s are all roughly the same distance away from the [[Atomic Nucleus|nucleus]]. | ||
| + | *The [[charge]] on the [[Atomic Nucleus|atomic nucleus]] increases as you move go across the [[period]] but the [[electron]] shielding caused by the two inner [[electron]]s remains the same. This causes the [[electron]]s to experience a greater [[force]] of [[attraction]] as you move along the [[period]], making it harder for the [[atom]]s to lose [[electron]]s and become [[ion]]s. | ||
| + | |||
| + | [[Nitrogen]], [[Oxygen]] and [[Fluorine]] can all gain [[electron]]s to become [[Negative Charge|negative]] [[ion]]s in certain [[Chemical Reaction|reaction]]s. | ||
| + | |||
| + | The [[reactivity]] increases as you go across the [[Period (Chemistry)|period]] because: | ||
| + | *The outer [[electron]]s are all roughly the same distance away from the [[Atomic Nucleus|nucleus]]. | ||
| + | *The [[charge]] on the [[Atomic Nucleus|atomic nucleus]] increases as you move go across the [[period]] but the [[electron]] shielding caused by the two inner [[electron]]s remains the same. This causes the [[electron]]s to experience a greater [[force]] of [[attraction]] as you move along the [[period]], making it easier for an [[atom]]s to gain more [[electron]]s to become [[ion]]s. | ||
|} | |} | ||
Revision as of 19:58, 5 December 2018
Contents
Key Stage 3
Meaning
A period is a row on the Periodic Table whose elements all have the same number of Electron Shells.
About Periods
- Atomic Number increases as you move along a period.
Trends within Periods
- The chemical and physical properties of elements change as you move along a period.
| Period 2 Melting Points | Period 3 Melting Points |
| There is a trend in the Melting Points as you move along the period. | A similar trend can be seen in the next period. |
Key Stage 4
Meaning
A period is a row on the Periodic Table whose elements all have the same number of Electron Shells.
About Periods
- Atomic Number increases as you move along a period.
- The number of the period is the same as the number of electron shells.
Trends within Periods
| For the first 3 elements Lithium, Beryllium and Boron all lose electrons in chemical reactions.
The reactivity decreases as you go across the period because:
Nitrogen, Oxygen and Fluorine can all gain electrons to become negative ions in certain reactions. The reactivity increases as you go across the period because:
|