1. Inside the atom By: Christian Valdelamar Maria Gonzalez

2. Atomism • Atomism is the theory that all objects in the universe are composed of very small indestructible building blocks. • Democritus and Leucippus taught that the hidden substances in all physical objects consists of different arrangements of atoms. • Democritus is given credit for the discovery of the model of atomism.

3. Atomism and the earth, fire, wind, water model • Aristotle came up with the idea that there were four different types of atoms.

4. Solid sphere model • In 1803, John Dalton viewed the atoms as a small solid sphere, he believed that: • Each element was composed of the same kind of atoms. • Each element was composed of different kinds of atoms . • Compounds are compounds are composed of atoms in specific ratios. • Chemical reactions are rearrangements of atoms. • He came to this conclusion by careful analysis.

5. Plum pudding model •The plum pudding model of the atom was proposed by J. J Thomson who discovered the electron in 1897. •Then later Thomson proposed the plum pudding model in 1904. • This model as show by the picture suggests that little electrons float around in a positive mass. That is where it gets the name plum pudding, the pudding is the positive and the plums are the positive charges.

6. Nuclear Model • Ernest Rutherford created the nuclear model by experimenting with the Gold Foil Experiment, believing that most alpha particles passed through the foil, but some of the particles bounced back.

7. Planetary model • In this model shows the atom moving around the nucleus going in many different directions. The orbits go around the nucleus but can’t get outside the pull toward the center. This pull keeps the atom together. Rutherford and Bohr’s model are similar.

8. Electron cloud model •This model was developed by Erwin Schrodinger base on Bohr’s model of the atoms. •He developed the probability function basically describes a cloud like region where the electron is likely to be found. • Based on this probability equation can best described as the cloud model. •The red dot in the middle represents the nucleus while the red dot around the outside represents an instance of the electron.

9. Cathode ray experiment From the observation made by J. J Thomson in the cathode ray experiment he concluded that the particles inside were all negative charged. This led to the development of the plum pudding model

10. Gold foil experiment • Ernest Rutherford did a brilliant experiment in which he fired alpha particles at a very thin gold foil. He got a somewhat shocking result, rather than all the particle passing straight trough the foil many were scattered off at large angles some even coming straight back. This led to the planetary model of the atom with electrons orbiting the nucleus like planets orbiting the sun