Atoms

Question 1

Radius of an atom

Answer 1

≈ 10^-10 m

Question 2

Sub atomic particles

Answer 2

Electron (-1)
Proton (+1)
Neutron (0)

Question 3

Mass number

Answer 3

Number of protons

Question 4

Atomic number

Answer 4

Number of protons + neutrons

Question 5

Isotopes

Answer 5

Different versions of the same element with the same number of protons, different number of neutrons

Question 6

Geiger-marsan experepment

Answer 6

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