Question

in rutherford's gold foil experiment what kind of particles in dense atomic nuclei caused some alpha particles to bounce straight back from the gold foil

Answer 1

In Rutherford's gold foil experiment, Nuclei in the gold atom caused some of the alpha particles to bounce straight back from the gold foil Alpha particles are positively charged as is the nucleus of atoms therefor repelling each other. Because the large spacing of the nucleus in the gold atoms only a small amount of alpha particles will collide directly with the nucleus, therefor only a small amount of alpha particles will be reflected back.

Answer 2

Answer:

Positive

Explanation:

"Rutherford directed beams of alpha particles (which are the nuclei of helium atoms and hence positively charged) at thin gold foil to test this model and noted how the alpha particles scattered from the foil. ... A very small number of alpha particles were deflected backwards!"

- scool revision website (Very cool website that provides diagrams.)

https://www.s-cool.co.uk/a-level/physics/atomic-structure/revise-it/rutherford-alpha-particle-scattering-experiment

"He decided to test this with a thin film of gold atoms. As expected, most alpha particles went right through the gold foil but to his amazement a few alpha particles rebounded almost directly backwards."

- iun.edu

Therefore, the nucleus is positively charged because the alpha particles are positively charged, (like charges repel.)