Can you write the nuclear decay equation for the beta decay of iodine-131?
The equation is ##””_53^131″I” → “”_54^131″Xe” + color(white)(l)_text(-1)^0″e”##
is a process in which a nucleus emits an electron.
The nuclear symbol for a β particle is ##color(white)(l)_text(-1)^0″e”##.
In any nuclear equation, the sum of the subscripts (atomic numbers, ##”Z”##) and the sum of the superscripts (atomic masses, ##”M”##) must be equal on each side of the equation.
For the β decay of iodine 131, we have
##””_53^131″I” → color(white)(l)_text(Z)^”M””X” + color(white)(l)_text(-1)^0″e”##
Hence
##131 = “M” + 0##, so ##”M” = 131##
##53 = “Z – 1″##, so ##”Z” = 53 + 1 = 54##
The element ##”X”## with ##”Z = 54″## is ##”Xe”##.
So the equation is
##””_53^131″I” → “”_54^131″Xe” + color(white)(l)_text(-1)^0″e”##
Note that in β decay, the product has the same but an that has increased by 1.
Here’s a video on writing β decay equations.