The atomic number of germanium (Ge) is 32, which means it has 32 electrons. The configuration of these electrons is:

```

1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^2

```

The valence electrons are the electrons in the outermost shell, which in the case of germanium are the four 4p electrons. So, the number of valence electrons in a germanium atom is 4.