The elements which do not occur in nature but are produced by nuclear reactions are called synthetic elements.
The elements technetium
(
T
c
)
(
, promethium
(
P
m
)
(
, and fracium
(
F
r
)
(
are synthetic elements .
Synthesiselement
Z
Nuclearreaction
Technetium
(
T
c
)
43
.
42
M
o
96
+
.
1
H
2
→
.
43
T
c
97
+
.
0
n
1
P
r
o
m
e
t
h
i
u
m
(
P
m
)
61
.
60
N
d
150
+
.
1
H
2
→
.
61
p
D
151
+
.
0
n
1
F
r
a
c
i
u
m
(
F
r
)
87
.
89
A
c
227
→
.
87
F
e
223
+
.
2
H
e
4
Synthesiselement
