Radioactive isotopes have been used commercially in: smoke detectors older watches with luminescent dials sterilization of food all of these applications

air quality

poor drinking water

and heavy polution

can lead to poor health

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer