What observations in the scattering experiment led Rutherford to make the following conclusions:

The nucleus has a positive charge.

In Rutherford's gold foil experiment, the structure of an atom was determined.

1. Rutherford used a thin gold foil and bombarded it with radioactive alpha particles and observed the results.
2. One of the conclusions made was that nucleus has positive charge.
3. The incident alpha particles were scattered in all directions at various angles. Though most of them passed undeflected, some got reflected back almost completely and with same intensity. This suggested that a dense center of atom, namely nucleus is present.
4. The fact that positively charged beams of alpha particle were completely repelled suggested that the nucleus has positive charge.