Struggling to understand the answer to this question.
When alpha particles are directed at a thin gold foil it is found that most of the alpha
particles go straight through undeflected. However a very small number are scattered
through angles greater than 90°.
Which of the following is not a valid conclusion?
The atom is mainly empty space.
The nucleus must be positively charged.
The nucleus must contain most of the mass of the atom.
There is a large charge concentration in the centre of the atom.
The answer is 2. I assumed that a negative nucleus would not scatter alpha particles in this way. Could it?