Hi, could someone tell me the beta decay of Indium 115? The only one I see is Sn, but that wouldn't balance out with the 115?

THANK YOU VERY MUCH:)

1 Answer
Mar 23, 2018

The equation is #""_49^115"In" → ""_50^115"Sn" + β#.

Explanation:

Your equation is

#""_49^115"In" → "?" + β#

It becomes easier to balance the equation if we replace the "?" with an element symbol #""_x^y"Z"#.

Then the equation becomes

#""_49^115"In" → ""_x^y"Z"" + β#

We should also recall that a β particle is an electron. Its nuclear symbol is #""_text(-1)^0"e"#.

The equation then becomes

#""_49^115"In" → ""_x^y"Z" + ""_text(-1)^0"e"#

The main point to remember in balancing nuclear equations is that the sums of the superscripts and the subscripts must be the same on each side of the equation.

Sum of superscripts: #115 = y + 0#, so #y =115#.

Sum of subscripts: #color(white)(ml)49 = x"-1"#, so #x = 50#.

We get

#""_49^115"In" → ""_50^115"Z" + ""_text(-1)^0"e"#

The atomic number of the element is 50, tin.

∴ The nuclear equation is

#""_49^115"In" → ""_50^115"Sn" + ""_text(-1)^0"e"#

If desired, you could re-insert the β symbol and get

#""_49^115"In" → ""_50^115"Sn" + β#

The equation is #color(blue)(""_49^115"In" → ""_50^115"Sn" + β)#.