Changes

[[Isotope]]s are [[atom]]s with of the same number of [[protonelement]]s (have the same number of [[elementproton]]s) but a different number numbers of [[neutron]]s.

: Each [[element]] has many [[isotope]]s but some are [[Stable Isotope|stable]] so they will exist for billions of years and others are [[Unstable Isotope|unstable]] so they [[Radioactive Decay|decay]] quickly into other [[isotope]]s or a different [[element]].

: The [[Periodic Table]] orders the [[element]]s due to their [[Chemical Property|chemical properties]] but since [[isotope]]s of the same [[element]] have the same [[Chemical Property|chemical properties]] then different [[isotope]]s are not included. Instead : On the [[Periodic Table]] an [[Mean Average|average]] [[Relative Atomic Mass|atomic mass]] is given based on the [[Relative Atomic Mass|mass]] of each [[isotope]] and how common it is.: To find the [[Mean Average|average]] [[Relative Atomic Mass|atomic mass]] the [[Relative Atomic Mass|mass]] of each [[isotope]] is considered along with the [[ratio]] of abundance.====Calculating the Average Relative Atomic Mass==== {| class="wikitable"| style="height:20px; width:300px; text-align:center;" |[[Chlorine]] has two common [[Stable Isotope|stable]] [[Isotope]]s; [[Chlorine-35]] and [[Chlorine-37]]. [[Chlorine-35]] is three times more common than [[Chlorine-37]] so the ratio is 3:1. Find the [[Mean Average|average]] [[Relative Atomic Mass|atomic mass]] of [[Chlorine]].| style="height:20px; width:300px; text-align:center;" |[[Lithium]] has two common [[Stable Isotope|stable]] [[Isotope]]s; [[Lithium-7]] and [[Lithium-6]].92.5% of all [[Lithium]] is the [[isotope]] [[Lithium-7]] while [[Lithium-6]] makes up only 7.5%. Find the [[Mean Average|average]] [[Relative Atomic Mass|atomic mass]] of [[Lithium]].|-| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities.''' Ratio: 3:1 3xChlorine-35 : 1xChlorine-37| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities.''' Ratio: 92.5:7.5 92.5xLithium-7 : 7.5xLithium-6|-| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].''' To find the [[Mean Average|average]]: <math>Average=\frac{35+35+35+37}{4}</math> <math>Average=\frac{35 \times 3 + 37 \times 1}{4}</math> <math>Average=35.5</math> So the [[Relative Atomic Mass]] of [[Chlorine]] is quoted as 35.5 on the [[Periodic Table]].| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].''' To find the [[Mean Average|average]]: <math>Average=\frac{7 \times 92.5 + 6 \times 7.5}{100}</math> <math>Average=6.925</math> So the [[Relative Atomic Mass]] of [[Lithium]] is quoted as 6.9, 6.93 or 6.925 depending on the [[precision]] of that particular [[Periodic Table]].|} ===References=======AQA==== :[https://www.amazon.co.uk/gp/product/0008158770/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158770&linkCode=as2&tag=nrjc-21&linkId=ec31595e720e1529e49876c3866fff6e ''Isotope, pages 109-10, 117, GCSE Physics; Student Book, Collins, AQA '']:[https://www.amazon.co.uk/gp/product/0008158770/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158770&linkCode=as2&tag=nrjc-21&linkId=ec31595e720e1529e49876c3866fff6e ''Isotope; definition, page 110, GCSE Physics; Student Book, Collins, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Isotopes, page 112, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Isotopes, page 124, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/0198359381/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359381&linkCode=as2&tag=nrjc-21&linkId=47c8d1ae58d8b3a5e2094cd447154558 ''Isotopes, page 17, GCSE Chemistry; Third Edition, Oxford University Press, AQA '']:[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac268 ''Isotopes, page 44, GCSE Physics; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1471851370/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851370&linkCode=as2&tag=nrjc-21&linkId=01c69b0ae058f809cf636033e6ba793e ''Isotopes, page 90, GCSE Physics, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/1471851354/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851354&linkCode=as2&tag=nrjc-21&linkId=9012a0d354024419214fb3ad5ac44ba0 ''Isotopes, pages 119-20, 340, GCSE Combined Science Trilogy 1, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/1782945571/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945571&linkCode=as2&tag=nrjc-21&linkId=9e29fad914244909903e5e93f8a01d167 ''Isotopes, pages 13, 21, GCSE Chemistry; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945962/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945962&linkCode=as2&tag=nrjc-21&linkId=476bb5c8d1dfb5c08ac81b6d4d1c98d8 ''Isotopes, pages 25, 26, 51, GCSE Chemistry, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/178294639X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294639X&linkCode=as2&tag=nrjc-21&linkId=51599bb45a2bfaf7c1b6a978b2ca2616 ''Isotopes, pages 27, 28, 51, GCSE Combined Science Trilogy; Chemistry, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1471851346/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851346&linkCode=as2&tag=nrjc-21&linkId=3ac654f4b0da781c49c855a1af4c92ea ''Isotopes, pages 4-5, GCSE Chemistry, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Isotopes, pages 96-97, 104-107, 109, GCSE Physics; Third Edition, Oxford University Press, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe10019 ''Isotopes, pages 97, 106, 198, GCSE Combined Science; The Revision Guide, CGP, AQA ''] ====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 ''Isomers, page 173, GCSE Chemistry, Pearson, Edexcel '']:[https://www.amazon.co.uk/gp/product/1782948163/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948163&linkCode=as2&tag=nrjc-21&linkId=0fdbfd5dd397d6e24a9dfb250f08587f ''Isotopes, page 155, GCSE Physics, 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 ''Isotopes, page 17, GCSE Chemistry; The Revision Guide, CGP, Edexcel '']:[https://www.amazon.co.uk/gp/product/1292120223/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1292120223&linkCode=as2&tag=nrjc-21&linkId=068ecf40278c32406a7f1c6e66751417 ''Isotopes, page 93, GCSE Physics, 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 ''Isotopes, pages 166-167, 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 ''Isotopes, pages 22-23, 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 ''Isotopes, pages 357, GCSE Combined Science, Pearson Edexcel '']:[https://www.amazon.co.uk/gp/product/1782948147/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782948147&linkCode=as2&tag=nrjc-21&linkId=f63dcd8345f4e49c717b39a228a36c7c ''Isotopes, pages 37, 38, GCSE Chemistry, CGP, Edexcel '']:[https://www.amazon.co.uk/gp/product/1782945733/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945733&linkCode=as2&tag=nrjc-21&linkId=2a2dbec9db6bf5766c0458d908fa0a52 ''Isotopes, pages 51, 53, GCSE Physics; The Revision Guide, CGP, 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 ''Isotopes, pages 80, 174, 176, GCSE Combined Science; The Revision Guide, CGP, Edexcel ''] ====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 ''Isotopes, pages 15, 31, Gateway GCSE Chemistry; The Revision Guide, CGP, OCR '']:[https://www.amazon.co.uk/gp/product/0198359837/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359837&linkCode=as2&tag=nrjc-21&linkId=3c4229e8b023b2b60768e7ea2307cc6f ''Isotopes, pages 170-171, 183, Gateway GCSE Physics, Oxford, OCR '']:[https://www.amazon.co.uk/gp/product/0198359829/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0198359829&linkCode=as2&tag=nrjc-21&linkId=90e8d7b4f039d53035238fa0320fe00b ''Isotopes, pages 28-29, Gateway GCSE Chemistry, Oxford, OCR '']:[https://www.amazon.co.uk/gp/product/1782945687/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945687&linkCode=as2&tag=nrjc-21&linkId=9a598e52189317a20311d7a632747bc9 ''Isotopes, pages 74, 77, 79, Gateway GCSE Physics; The Revision Guide, CGP, 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 ''Isotopes, pages 86, 195, Gateway GCSE Combined Science; The Revision Guide, CGP, OCR '']