# Nuclear transition notation

I have a question which asks me to determine what x is for the following nuclear transition

$$^{29}Si(\alpha, n)X$$

But I don't have any idea what this notation implies.

Another example:

$$^{111}Cd(n,x)^{112}Cd$$

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$^{29}Si(\alpha, n)X$ means the nuclear reaction starting with $^{29}Si$, having an $\alpha$ particle go in and a neutron come out to produce $X$. That means the atomic number must increase by 2 and atomic weight by 3.
Similarly $^{111}Cd(n,x)^{112}Cd$ means the reaction starts with $^{111}Cd$, a neutron goes in, something comes out and you end up with $^{112}Cd$.
@Chris: That notation carries rather more information to an experimenter than John describes here, it's just that none of it is relevant to this particular question. It's the information on what is and is not measured that this form is preferred over, say, $^{29}\mathrm{Si} + \alpha \to n + X$. – dmckee Mar 7 '13 at 16:52