The Nuclear Atom Flashcards
What was the setup of the Alpha Scattering Experiment?
A source of alpha particles was fired at a gold foil with a detector that was was rotating around them to detect how many particles are deflected at different angles.
What were the observations that were discovered from the Alpha scattering experiment?
1 . Most of the alpha particles went straight through the gold foil, which suggested that most of the atom is an empty space.
- Few numbers of alpha particles deflected at large angles ( bigger than 90), which suggested that there was a positive charge in the centre because it repelled the positive alpha particles.
In the Alpha Scat Experiment what is the relationship between n ( number of alpha particles / unit time) and theta
n drops quickly with increasing in the angle of deflection theta.
This means that they are inversely proportional to each other.
Atomic structure: what is the diameter of the atom?
The diameter of the atom is 1*10^-10m
Atomic structure: what is the diameter of the nucleus?
The diameter of the nucleus is 1*10^-15
Closest approach distance: what does this approach and how can we calculate it?
This approach shows that :
1. Some of the alpha particles were scattered straight back fromm the gold foil , which is due to the electrostatic repulsion between the alpha particles and the gold foil.
- At the point of the closest approach,r, the repulsive forece reduces the speed of the alpha particle to zero momentarily, this is because the alpha particle can not get more closer to the gold foil.
- At this point tha KE of the alpha particle was equal to the Electric potential energy, due ro conservation of energy.
- To able to find the closest approach distance we can equal the KE to EPE (1/2mv^2 =
Qq/4pip0*r) and rearrange for r
AZX Notation: what does A, Z and X mean?
A is the nucleon number or mass number
Z is the proton number or the atomic number
X is the element
What is an Isotope?
It is an atom of the same element that has an equal number of protons but a different number of neutrons
What does having a different neutron number mean in terms of charge and mass of the atom?
Having multiple elements will not change the charge (charge is constant) of the atom it will only affect the mass of it
