Changes

A [['''Group]] ''' is a column on the [[Periodic Table]] with [[element]]s with the same number of [[electron]]s on the [[Outer Shell]].

: The [[elementHelium]], in [[Group 0]] is an exception to this rule as it has 2 [[electron]]s are arranged in its [[Outer Shell]].: The [[groupelement]]s are arranged '''groups''' of similar [[Chemical PropertiesProperty|chemical properties]].: [[Element]]s have similar [[Chemical PropertiesProperty|chemical properties]] when they have the same number of [[electron]]s in the [[Outer Shell]].

====Trends within groups====The [[Chemical Property|chemical properties]] of [[element]]s within a [['''group] ''' are similar. However, the [[reactivity]] within a [['''group]] ''' changes as you move up or down the [[Period (Chemistry)|period]]s.*[[Group 1]]: The [[Alkali Metal]]s all react strongly with water. The [[reactivity]] increases as you go down the [['''group]]'''.*[[Group 2]]: The [[Alkali Earth Metal]]s all react strongly with steam and acids. The [[reactivity]] increases as you go down the [['''group]]'''.*[[Group 7]]: The [[Halogen]]s all act as bleaching agents and kill bacteria. The reactivity decreases as you go down the [['''group]]'''.

The [[Physical Property|physical properties]] of [[element]]s within a '''group''' are similar. However, the property changes gradually as you move down the '''group'''. ==Key Stage 4=====Meaning===A '''Group''' is a column on the [[Periodic Table]] with [[element]]s with the same number of [[electron]]s on the [[groupOuter Shell]]. ===About Groups===: [[Helium]], in [[Group 0]] is an exception to this rule as it has 2 [[electron]]s in its [[Outer Shell]].: The [[element]]s were oringally arranged '''groups''' of similar [[Chemical Property|chemical properties]].: It was later discovered that [[element]]s have similar [[Chemical Property|chemical properties]] when they have the same number of [[electron]]s in their [[Outer Shell]]s. {| class="wikitable"|-|[[File:PeriodicTableGroups.png|center|600px]]|}===Trends within groups===The [[Chemical Property|chemical properties]] of [[element]] s within a '''group''' are similar. However, the property [[reactivity]] within a '''group''' changes gradually as you move up or down the [[Period (Chemistry)|period]]s due to the number of [[Electron Shell]]s.====[[Group 1]]: The [[Alkali Metal]]=========Chemical Properties=====: '''Alkali Metals''' are all highly [[Reactivity|reactive]] and will [[Oxidation|oxidise]] quickly in the presence of [[Oxygen]].: '''Alkali Metals''' all [[Chemical Reaction|react]] strongly with [[water]] to produce [[Metal Hydroxide|metal hydroxides]] and [[Hydrogen]] [[gas]].: '''Alkali Metals''' all produce strong [[alkali]]s.{| class="wikitable"|-|[[File:Group1ElectronShells.png|center|100px]]| style="height:20px; width:500px; text-align:left;" |In a [[Chemical Reaction|chemical reaction]] the [[electron]] in the [[Outer Shell|outer shell]] is lost. The [[reactivity]] increases as you go down the groupbecause:*The outer [[electron]] is further away from the [[Atomic Nucleus|nucleus]] with each additional [[Electron Orbital|electron shell]] making the [[force]] of [[attract]]ion weaker. This makes it easier for an [[atom]] to lose it's outer [[electron]].*Even though the [[Electrical Charge|charge]] of the [[Atomic Nucleus|nucleus]] increases the outer [[electron]] is shielded from most of the [[Positive Charge|positive charge]] of the [[Atomic Nucleus|nucleus]] by [[electron]]s in the inner shells.|}=====Physical Properties=====: '''Alkali Metals''' have a low [[density]] compared to other [[metal]]s.: '''Alkali Metals''' are all [[solid]] at [[Room Temperature|room temperature]] but have a low [[Melting Point|melting point]] compared to other [[metal]]s.: '''Alkali Metals''' are soft and can be easily cut.: '''Alkali Metals''' all appear shiny (before they [[oxidation|oxidise]]). ====[[Group 7]]: The [[Halogen]]s=========Chemical Properties=====: The [[reactivity]] of '''Halogens''' decreases as you go down the [[Periodic Table]].: '''Halogens''' all [[Chemical Reaction|react]] strongly as [[Bleaching Agent|bleaching agents]].: '''Halogens''' all produce [[acid]]s when combined with [[Hydrogen]].: '''Halogens''' are [[toxic]] to [[bacteria]] and are used in [[disinfectant]]s.{| class="wikitable"|-|[[File:Group7ElectronShells.png|center|100px]]| style="height:20px; width:500px; text-align:left;" |In a [[Chemical Reaction|chemical reaction]] an extra [[electron]] is added to the [[Outer Shell|outer shell]]. The [[reactivity]] decreases as you go down the group because:*The outer [[electron]]s are further away from the [[Atomic Nucleus|nucleus]] with each additional [[Electron Orbital|electron shell]] making the [[force]] of [[attract]]ion weaker. This makes it less able to gain an extra [[electron]].*Even though the [[Electrical Charge|charge]] of the [[Atomic Nucleus|nucleus]] increases the outer [[electron]]s are shielded from most of the [[Positive Charge|positive charge]] of the [[Atomic Nucleus|nucleus]] by [[electron]]s in the inner shells.|}=====Physical Properties=====The [[Physical Property|physical properties]] of '''Halogens''' changes significantly as you go down the [[Periodic Table]]:*[[Fluorine]] - A yellow [[gas]] at [[Room Temperature|room temperature]].*[[Chlorine]] - A green [[gas]] at [[Room Temperature|room temperature]].*[[Bromine]] - A brown [[liquid]] at [[Room Temperature|room temperature]].*[[Iodine]] - A purple [[solid]] at [[Room Temperature|room temperature]].*[[Astatine]] -A dark purple [[solid]] at [[Room Temperature|room temperature]].: The [[density]], [[Melting Point|melting point]] and [[Boiling Point|boiling point]] all increase as you go down the [[Periodic Table]]. ====[[Group 0]]: The [[Noble Gases]]=========Chemical Properties=====: The '''Nobel Gases''' are all [[inert]] (unreactive) because they have a full [[Outer Shell|outer shell]]. =====Physical Properties=====: The '''Nobel Gases''' are all [[gas]]es at [[Room Temperature|room temperature]].: The [[density]] and [[Boiling Point|boiling point]] all increase as you go down the [[Periodic Table]]. ===References=======Edexcel==== :[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Groups (of the periodic table), page 173, GCSE Combined Science, Pearson Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''Groups (of the periodic table), page 29, GCSE Chemistry, Pearson, Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''Groups (of the periodic table); group 0 elements, pages 134-135, GCSE Chemistry, Pearson, Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Groups (of the periodic table); group 0 elements, pages 248-249, GCSE Combined Science, Pearson Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''Groups (of the periodic table); group 1 elements, pages 128-129, GCSE Chemistry, Pearson, Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Groups (of the periodic table); group 1 elements, pages 242-243, GCSE Combined Science, Pearson Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''Groups (of the periodic table); group 7 elements, pages 130-131, 132-133, GCSE Chemistry, Pearson, Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Groups (of the periodic table); group 7 elements, pages 244-245, 246-247, GCSE Combined Science, Pearson Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120193/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120193&linkCode=as2&tag=nrjc-21&linkId=572df39392fb4200db8391d98ae6314e ''Groups (of the periodic table); valency, page 185, GCSE Combined Science, Pearson Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120215/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120215&linkCode=as2&tag=nrjc-21&linkId=8f96ddb76196848bafdb124354e4cf77 ''Groups (of the periodic table); valency, page 41, GCSE Chemistry, Pearson, Edexcel '']:[https://www.amazon.co.uk/gp/product/1782945741/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945741&linkCode=as2&tag=nrjc-21&linkId=30da4f2178da182547b62a7329d13b57 ''Groups (periodic table), pages 81-83, 123, 124, 126, GCSE Combined Science; The Revision Guide, CGP, Edexcel '']:[https://www.amazon.co.uk/gp/product/1782945725/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945725&linkCode=as2&tag=nrjc-21&linkId=694be7494de75af3349537d34e13f7f0 ''Groups, pages 18-20, 73, 74, 76, GCSE Chemistry; The Revision Guide, CGP, Edexcel ''] ====OCR====:[https://www.amazon.co.uk/gp/product/1782945695/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945695&linkCode=as2&tag=nrjc-21&linkId=ceafcc80bcad6b6754ee97a0c7ceea53 ''Groups (in the periodic table), pages 87-89, 121-125, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR '']:[https://www.amazon.co.uk/gp/product/1782945679/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945679&linkCode=as2&tag=nrjc-21&linkId=a2db42f7b4bdf10cafaafa3bb9120940 ''Groups, pages 16-18, 51, 52, 54, Gateway GCSE Chemistry; The Revision Guide, CGP, OCR '']