Atoms Flashcards
1
Q
Radius of an atom
A
≈ 10^-10 m
2
Q
Sub atomic particles
A
Electron (-1)
Proton (+1)
Neutron (0)
3
Q
Mass number
A
Number of protons
4
Q
Atomic number
A
Number of protons + neutrons
5
Q
Isotopes
A
Different versions of the same element with the same number of protons, different number of neutrons
6
Q
Geiger-marsan experepment
A
1) alpha particles fired at gold foil
2) vast majority passed straight through gold foil but a small number were deflected
3) this proved that the plum pudding model could not be correct as the positive ball would cancel out the negative electrons so alpha particles would have passed through, feeling no attraction or repulsion