2. By: Jeremy Aponte, Javier Candelaria, Eric Mendoza

4. The alchemists were a group of European scientists about 850 years ago. Their work developed into modern chemistry (we still use their work today). Their purpose was to change ordinary materials into gold. Although they failed since doing this is not possible even now.

5. John Dalton was a scientist in England during 1808. He discovered and described atoms as tiny particles that could not be divided. His work developed off of the ideas of Democritus from Greece.

6. J.J Thompson was a scientist who lived in England and discovered that electrons were smaller particles of an atom and were negatively charged during 1897. He did this because he knew atoms were neutrally charged but he could not find the positive particle.

7. Ernest Rutherford was a scientist who lived in England and in 1911 conducted an experiment to isolate the positive particles in an atom. He declared the atom as mostly empty space but also declared that it had a dense central core.

8. Niels Bohr Niels Bohr was an English scientist who in 1913 proposed that electrons traveled in fixed paths around the nucleus. Today the Bohr model is still used to find the number of electrons orbiting the nucleus of an atom. He decided to work on this because he wanted to show why negative electrons were sucked into an atoms nucleus.

9. Electron Cloud Model The electron cloud model is an atom model wherein electrons are no longer depicted as particles moving around the nucleus in a fixed orbit. The electrons travel so fast they appear to form a cloud around the nucleus. Scientists cannot predict where they will be, however and the electrons travel around the nucleus in random orbits which doesn’t allow the particles to be depicted.