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: The [[Nuclear Model]] was first proposed by [[Ernest Rutherford]] after he successfully disproved the [[Plum Pudding Model]] of the [[atom]] using his [[Rutherford's Alpha Scattering Experiment|alpha scattering experiment]].
: In the [[Nuclear Model]] most of the [[atom]] is empty space. The majority of the [[mass]] of the [[atom]] is concentrated in a small central [[Atomic Nucleus|nucleus]]. This central [[Atomic Nucleus|nucleus]] has a strong [[Positive Charge|positive charge]] while [[Negative Charge|negatively charged]] [[electron]]s [[orbit]] the [[Atomic Nucleus|nucleus]].
===Evidence for the Nuclear Model===
: In [[Rutherford's Alpha Scattering Experiment]] several observations about the path of [[Alpha Particle|alpha particles]] through a thin sheet of [[Gold]] foil that led to the development of the [[Nuclear Model]]:
{| class="wikitable"
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| style="height:20px; width:200px; text-align:center;" |'''Observation'''
| style="height:20px; width:200px; text-align:center;" |'''Conclusion'''
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| style="height:20px; width:200px; text-align:center;" |Most of the [[Alpha Particle|alpha particle]]s pass straight through the foil.
| style="height:20px; width:200px; text-align:center;" |The [[atom]] must be mostly empty space.
|-
| style="height:20px; width:200px; text-align:center;" |Some of the [[Alpha Particle|alpha particle]]s were deflected by a small angle.
| style="height:20px; width:200px; text-align:center;" |The [[mass]] of the [[atom]] must be concentrated in an extremely small [[Volume (Space)|volume]] in the centre.
|-
| style="height:20px; width:200px; text-align:center;" |A very small number of [[Alpha Particle|alpha particle]]s came back in the direction of the detector. (Deflected more than 90°.)
| style="height:20px; width:200px; text-align:center;" |The centre of an [[atom]] must have a strong positive charge.
The [[electron]]s must not be in the centre of the [[atom]], they must be [[orbit]]ing the [[nucleus]].
|}
hey discovered that most of the [[Alpha Particle|alpha particle]]s went through in a straight line. A significant number were [[deflect]]ed and a very small number bounced off the [[Gold]] back towards the [[Alpha Particle|alpha]] source.