Mendeleev's Periodic Table - Revision history

NRJC at 14:09, 5 December 2018

2018-12-05T14:09:04Z

NRJC at 14:07, 5 December 2018

2018-12-05T14:07:55Z

NRJC: Created page with "==Key Stage 4== ===Meaning=== '''Mendeleev's Periodic Table''' is the basis for the modern Periodic Table but arranged elements by Relative Atomic Mass instead of..."

2018-12-05T14:00:36Z

Created page with "==Key Stage 4== ===Meaning=== '''Mendeleev's Periodic Table''' is the basis for the modern Periodic Table but arranged elements by Relative Atomic Mass instead of..."

New page

==Key Stage 4==
===Meaning===
'''Mendeleev's Periodic Table''' is the basis for the modern [[Periodic Table]] but arranged [[element]]s by [[Relative Atomic Mass]] instead of [[Atomic Number]].

===About Mendeleev's Periodic Table===
: Scientists always try to look for patterns to help arrange complicated problems. Many different [[element]]s had been discovered so scientists wanted to arrange them based on patterns they noticed. Some scientists arranged them by patterns in [[Chemical Property|chemical properties]] while others tried to arrange them by patterns in [[Physical Properties]] like [[Melting Point]] or [[Relative Atomic Mass]].
: A scientist called John Dalton, who created the [[Dalton Model]] of the [[atom]], arranged [[element]]s by their [[Relative Atomic Mass]].
: A scientist called John Newlands arranged [[element]]s by [[Relative Atomic Mass]] but because he noticed that ever 8th [[element]] had similar [[Chemical Property|chemical properties]] he arranged them into what he called 'octaves'. However, he had not taken into account the possibility that some [[element]]s had not been discovered, so he placed some [[element]]s into the wrong groups just to fit the pattern he thought he had seen.
: [[Mendeleev]] was the first to place gaps where the [[element]]s did not fit the pattern but still arranged them by both their [[Chemical Property|chemical properties]] and [[Relative Atomic Mass]]. This enabled [[Mendeleev]] to [[Prediction|predict]] the existence of [[element]]s that had not yet been discovered.
: '''Mendeleev's Periodic Table''' was proven (nearly) correct when new [[element]]s were discovered that fit in the the gaps he had left. This ability of his table to predict the [[property|properties]] of new [[element]]s was what convinced other scientists his [[Periodic Table]] was correct.
: Once the structure of the [[atom]] was investigated by physicists it was discovered that '''Mendeleev's Periodic Table''' was not entirely correct and so the modern [[Periodic Table]] was created which ordered the [[element]]s by [[Atomic Number]] instead of [[Relative Atomic Mass]].

@@ Line 2: / Line 2: @@
 ===Meaning===
 '''Mendeleev's Periodic Table''' is the basis for the modern [[Periodic Table]] but arranged [[element]]s by [[Relative Atomic Mass]] instead of [[Atomic Number]].
+{| class="wikitable"
 ===About Mendeleev's Periodic Table===
 : Scientists always try to look for patterns to help arrange complicated problems. Many different [[element]]s had been discovered so scientists wanted to arrange them based on patterns they noticed. Some scientists arranged them by patterns in [[Chemical Property|chemical properties]] while others tried to arrange them by patterns in [[Physical Properties]] like [[Melting Point]] or [[Relative Atomic Mass]].

@@ Line 5: / Line 5: @@
 ===About Mendeleev's Periodic Table===
 : Scientists always try to look for patterns to help arrange complicated problems. Many different [[element]]s had been discovered so scientists wanted to arrange them based on patterns they noticed. Some scientists arranged them by patterns in [[Chemical Property|chemical properties]] while others tried to arrange them by patterns in [[Physical Properties]] like [[Melting Point]] or [[Relative Atomic Mass]].
-: A scientist called John Dalton, who created the [[Dalton Model]] of the [[atom]], arranged [[element]]s by their [[Relative Atomic Mass]].
+: In 1808 a scientist called John Dalton, who created the [[Dalton Model]] of the [[atom]], arranged [[element]]s by their [[Relative Atomic Mass]].
-: A scientist called John Newlands arranged [[element]]s by [[Relative Atomic Mass]] but because he noticed that ever 8th [[element]] had similar [[Chemical Property|chemical properties]] he arranged them into what he called 'octaves'. However, he had not taken into account the possibility that some [[element]]s had not been discovered, so he placed some [[element]]s into the wrong groups just to fit the pattern he thought he had seen.
+: In 1864 a scientist called John Newlands arranged [[element]]s by [[Relative Atomic Mass]] but because he noticed that ever 8th [[element]] had similar [[Chemical Property|chemical properties]] he arranged them into what he called 'octaves'. However, he had not taken into account the possibility that some [[element]]s had not been discovered, so he placed some [[element]]s into the wrong groups just to fit the pattern he thought he had seen.
-: [[Mendeleev]] was the first to place gaps where the [[element]]s did not fit the pattern but still arranged them by both their [[Chemical Property|chemical properties]] and [[Relative Atomic Mass]]. This enabled [[Mendeleev]] to [[Prediction|predict]] the existence of [[element]]s that had not yet been discovered.
+: In 1869 [[Mendeleev]] was the first to place gaps where the [[element]]s did not fit the pattern but still arranged them by both their [[Chemical Property|chemical properties]] and [[Relative Atomic Mass]]. This enabled [[Mendeleev]] to [[Prediction|predict]] the existence of [[element]]s that had not yet been discovered.
-: '''Mendeleev's Periodic Table''' was proven (nearly) correct when new [[element]]s were discovered that fit in the the gaps he had left. This ability of his table to predict the [[property|properties]] of new [[element]]s was what convinced other scientists his [[Periodic Table]] was correct.
+: '''Mendeleev's Periodic Table''' was proven (nearly) correct when new [[element]]s were discovered that fit in the the gaps he had left. This ability of his table to predict the [[property|properties]] of new [[element]]s was what convinced other scientists his [[Periodic Table]] was (nearly) correct.
-: Once the structure of the [[atom]] was investigated by physicists it was discovered that '''Mendeleev's Periodic Table''' was not entirely correct and so the modern [[Periodic Table]] was created which ordered the [[element]]s by [[Atomic Number]] instead of [[Relative Atomic Mass]].
+: There were some problems with '''Mendeleev's Periodic Table''' that kept scientists skeptical of it. One such problem was that [[Argon]] has a greater [[Relative Atomic Mass]] than [[Potassium]] which would put [[Argon]] in the [[Alkali Metal]]s.