[问答题]
Decay series, such as tha tc l7w 9aw04(dwb mbncvm2c 3kb8;bh2t shown in(Fig.w( ,afx.q(, *ocjemgl Below), can be classified into four families, depending onmwoe,q(( j *lxa f,c.g whether the mass numbers have the form $4n$, $4n+1$, $4n+2$, or $4n+3$, where $n$ is an integer. Justify this statement and show that for a nuclide in any family, all its daughters will be in the same family.
