Thomson proposed that negatively charged particle were randomly dispersed in a positively charged atom, much like
pieces of plum in plum pudding. rutherford shot positively charged alpha particles at thin gold foil, most of the
particles passed through unaffected.

answer:

in 1917 (in experiments reported in 1919), rutherford proved that the hydrogen nucleus is present in other nuclei, a result usually described as the discovery of the proton. earlier, rutherford learned to create hydrogen nuclei as a type of radiation produced as a yield of the impact of alpha particles on hydrogen gas; these nuclei were recognized by their unique penetration signature in air and their appearance in scintillation detectors. these experiments began when rutherford noticed that when alpha particles were shot into air (mostly nitrogen), his scintillation detectors displayed the signatures of typical hydrogen nuclei as a product. after experimentation rutherford traced the reaction to the nitrogen in air, and found that the effect was larger when alphas were produced into pure nitrogen gas. rutherford determined that the only possible source of this hydrogen was the nitrogen, and therefore nitrogen must contain hydrogen nuclei. one hydrogen nucleus was knocked off by the impact of the alpha particle, producing oxygen-17 in the process. this was the first reported nuclear reaction,    

in 1920, ernest rutherford conceived the possible existence of the neutron. in particular, rutherford examined the disparity found between the atomic number of an atom and its atomic mass. his explanation for this was the existence of a neutrally charged particle within the atomic nucleus. he considered the neutron to be a neutral double consisting of an electron orbiting a proton. in 1932, james chadwick showed uncharged particles in the radiation he used. these particles had a similar mass as protons, but did not have the same characteristics as protons. chadwick followed some of the predictions of rutherford, the first to work in this then unknown field.

step-by-step explanation:

i think 1: 2

step-by-step explanation:

for the friend request.

when a figure, such as triangle (xyz) is reflected over the line y = x to create x'y'z' the x-coordinates and y-coordinates of the original image (pre-image) will be reversed for the image. (e.g., (x, y) > (y, x)) this means that the pre-image position of the x- and y-coordinates switch places which in turn provides a mirror like image of the original xyz.  

i notice that when i draw a line segment from x to x', that the points are parallel from each other -- they are exactly across from each other and do not intersect with any other points.  

yes, think i would see the same characteristic if you drew the line segment connecting y with the reflecting line and then y' with the reflecting line because of the essence of reflections. because it is a mirror image, each point was effected the same way which leads me to conclude that they same would apply to y and y'.