Rutherford explains the model of atoms. According to him, protons and neutrons are present inside the nucleus and electrons revolve around the nucleus in a orbit.
The nucleus is made of proton and neutron. Most of the atom mass is located inside the nucleus. The alpha particles are deflected back from the center of the atoms that contains positively charged protons.
To find the probability we can draw a 4-square Punnett square using the parents' alleles for the gene. If you want a more detailed explanation I would be glad to help :)
