Presentation is loading. Please wait.

Presentation is loading. Please wait.

The Parts of an Atom.

Similar presentations

Presentation on theme: "The Parts of an Atom."— Presentation transcript:

1 The Parts of an Atom

2 J.J. Thomson He experimented with cathode ray tubes

3 He passed electricity through the tube and discovered the first subatomic particle – the electron
He developed the plum pudding model of an atom

4 Plum Pudding Model

5 Robert Millikan He determined that the electron has a negative charge
He determined the mass of the electron

6 Ernest Rutherford He proved the plum pudding model was incorrect with the gold foil experiment

7 Gold Foil Experiment positive alpha particles


9 He discovered the nucleus of the atom!
The nucleus is the dense, positively charged center of the atom He came up with the Nuclear Atomic Model

10 Nuclear Atomic Model Nucleus Electron

11 Years later, Rutherford discovered the proton
proton = a positively charged particle inside the nucleus + nucleus proton

12 James Chadwick worked with Rutherford
discovered the neutron – a particle in the nucleus with the SAME MASS as a proton, but with NO charge (it’s neutral)!

13 Modern Atomic Structure
spherically shaped most of atom’s mass is in the nucleus (99.7%) nucleus surrounded by negative electrons

14 Atoms have no charge (they are electrically neutral) because the number of protons is equal to the number of electrons 3 protons (+) 3 electrons (-) + -

15 *Electron has the least mass
particle symbol location charge mass (g) relative mass electron e – in space around nucleus 9.11 x 10 – 28 _1__ 1840 proton p+ inside + 1.673 x 10 – 24 1 neutron n0 no *Electron has the least mass

16 You Made It!!!

Download ppt "The Parts of an Atom."

Similar presentations

Ads by Google