Nuclear Composition Not Revealed by Scattering Steps:

• Observe that most α-particles pass undeflected, indicating atoms are mostly empty space.
• Note small-angle deflections from distant interactions and large-angle rebounds from close encounters with a central massive region.
• Analyze rebounds as Coulomb repulsion, requiring a small, dense, positively charged core to deflect heavy α-particles significantly.
• Conclude the experiment infers concentrated mass and positive charge but reveals nothing about neutral particles like neutrons.

Why B is correct:

• Neutrons, being uncharged, do not interact via the electromagnetic force observed in α-scattering; their existence was confirmed later by Chadwick's 1932 experiment using neutral radiation.

Why the others are wrong:

• A: Large deflections of massive α-particles require a concentrated massive nucleus for momentum transfer.
• C: Repulsive scattering follows Rutherford's formula for Coulomb interaction between positive α-particles and a positively charged nucleus.

Final answer: B