atomic mass
element
symbol
element
atomic mass
100

16

Sulfur

100

Be

Beryllium 

100

Cesium

Cs

100

Eu

Europium

100

53

Iodine

200

23

Vanadium

200

Kr

Krypton

200

Samarium

Sm

200

Xe

Xenon

200

34

Selenium

300

32

Germanium

300

Y

Yttrium

300

Gadolinium

Gd

300

Ag

Silver

300

41

Niobium

400

40

Zirconium

400

Ru

Ruthenium

400

Ytterbium

Yb

400

Mo

Molybdenum 

400

66

Dysprosium

500

43

Technetium

500

Sn

Tin

500

Tungsten

W

500

Tb

Terbium

500

59

Praseodymium