What are synthetic elements?

Sythetic elements are those with half lifes to small to be found in nature, they are manmade and generally fairly unstable.
The synthetic elements are:

All elements with atomic numbers 1 through 98 are naturally occurring at least in trace quantities, but the following elements are usually produced through synthesis. Except for francium, they were all discovered through synthesis before being found in nature.
Element nameChemical
Symbol
Atomic
Number
First definite
discovery
TechnetiumTc431936
PromethiumPm611945
AstatineAt851940
FranciumFr871939
NeptuniumNp931940
PlutoniumPu941940
AmericiumAm951944
CuriumCm961944
BerkeliumBk971949
CaliforniumCf981950



The following elements do not occur naturally on Earth. All are transuranium elements and have atomic numbers of 99 and higher.

Element nameChemical
Symbol
Atomic
Number
First definite
synthesis
EinsteiniumEs991952
FermiumFm1001952
MendeleviumMd1011955
NobeliumNo1021966
LawrenciumLr1031961
RutherfordiumRf1041966 (USSR), 1969 (USA) *
DubniumDb1051968 (USSR), 1970 (USA) *
SeaborgiumSg1061974
BohriumBh1071981
HassiumHs1081984
MeitneriumMt1091982
DarmstadtiumDs1101994
RoentgeniumRg1111994
CoperniciumCn1121996
UnuntriumUut1132003
FleroviumFl1141999
UnunpentiumUup1152003
LivermoriumLv1162000
UnunseptiumUus1172010
UnunoctiumUuo1182002