Comparison between the scandium surface abundance of our models without mass loss and the observed values of Table 1. The abundances are expressed as the difference between the logarithm of the actual value relative to H and the initial one. The colours of the tracks refer to the same transport process assumptions as in Fig. 4 and are recalled in the lower panel. For the sake of legibility, an offset has been added to the abscissa for stars of same age. The horizontal thin dotted line represents the initial abundance.