Difference between revisions of "Periodic Table"
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: The modern [[Periodic Table]] was arranged by a scientist called [[Mendeleev]]. Others had tried to arrange all the [[element]]s before, but [[Mendeleev]] was the first to arrange by both [[Atomic Number]] and [[Chemical Properties of Elements|chemical properties]]. | : The modern [[Periodic Table]] was arranged by a scientist called [[Mendeleev]]. Others had tried to arrange all the [[element]]s before, but [[Mendeleev]] was the first to arrange by both [[Atomic Number]] and [[Chemical Properties of Elements|chemical properties]]. | ||
: The columns of the [[Periodic Table]] are called [[Group]]s. | : The columns of the [[Periodic Table]] are called [[Group]]s. | ||
− | : The rows of the [[Periodic Table]] are called [[Period]]s. | + | : The rows of the [[Periodic Table]] are called [[Period (Chemistry)|Period]]s. |
{| class="wikitable" | {| class="wikitable" | ||
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====Trends within groups==== | ====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]]s. | + | 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 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 2]]: The [[Alkali Earth Metal]]s all react strongly with steam and acids. The [[reactivity]] increases as you go down the [[group]]. |
Revision as of 09:18, 1 October 2018
Contents
Key Stage 3
Meaning
The Periodic Table is a chart listing all the known elements arranged in order of Atomic Number and in columns of elements with similar properties.
About The Periodic Table
- The modern Periodic Table was arranged by a scientist called Mendeleev. Others had tried to arrange all the elements before, but Mendeleev was the first to arrange by both Atomic Number and chemical properties.
- The columns of the Periodic Table are called Groups.
- The rows of the Periodic Table are called Periods.
Groups
- The elements are arranged groups of similar Chemical Properties.
- Elements have similar Chemical Properties when they have the same number of electrons in the Outer Shell.
Trends within groups
The chemical properties of elements within a [[group] are similar. However, the reactivity within a group changes as you move up or down the periods.
- Group 1: The Alkali Metals all react strongly with water. The reactivity increases as you go down the group.
- Group 2: The Alkali Earth Metals all react strongly with steam and acids. The reactivity increases as you go down the group.
- Group 7: The Halogens all act as bleaching agents and kill bacteria. The reactivity decreases as you go down the group.
- Group 0: The Noble Gases are all inert (unreactive).
The physical properties of elements within a group are similar. However, the property changes gradually as you move down the group.
Periods
- The periods are arranged by the number of Electron Shells.
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. |