A period 7 element is one of the chemical elements in the seventh row (or period) of the periodic table of the elements and all have 7 electron shells.
All elements of period 7 are radioactive. This period contains the heaviest element which occurs naturally on earth, uranium. Most of the subsequent elements in the period have been synthesized artificially. Whilst some of these (e.g. plutonium) are now available in tonne quantities, most are extremely rare, having only been prepared in microgram amounts or less. Some of the later elements have only ever been identified in laboratories in quantities of a few atoms at a time.
A special property of period 7 is that the usual periodic repetition of chemical properties of the elements breaks down for the last elements of this period: Group 14 element ununquadium appears to be a noble gas instead of a poor metal, and group 18 element ununoctium probably is not a noble gas.[1] This is due to relativistic effects appearing for very heavy atoms.
The period 7 elements are:
| Group | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| # Name |
87 Fr |
88 Ra |
89-103 | 104 Rf |
105 Db |
106 Sg |
107 Bh |
108 Hs |
109 Mt |
110 Ds |
111 Rg |
112 Uub |
113 Uut |
114 Uuq |
115 Uup |
116 Uuh |
(117) (Uus) |
118 Uuo |
| e--conf. | ||||||||||||||||||
| Actinides | 89 Ac |
90 Th |
91 Pa |
92 U |
93 Np |
94 Pu |
95 Am |
96 Cm |
97 Bk |
98 Cf |
99 Es |
100 Fm |
101 Md |
102 No |
103 Lr |
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| e--conf. | ||||||||||||||||||
Colors in the periodic table show element categories
| Metals | Metalloids | Nonmetals | ||||||
| Alkali metals | Alkaline earth metals | Inner transition elements | Transition elements | Other metals | Other nonmetals | Halogens | Noble gases | |
| Lanthanoids | ||||||||
| Actinoids | (Unknown type) | |||||||
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References
- ^ See references in the articles Ununquadium, Ununoctium
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