The atomic theories states that all matter is made up of tiny indivisible particles called atoms.
APPLICATIONS OF ATOMIC ENERGY
He didn’t believe that the world and universe were composed of atoms. He taught that there were four elements that composed all materials that could be found on Earth.Those four elements were Earth, Water, Air, and Fire. Experiment. Determine which substances contained more or less of each element. He taught that there were four different category descriptions hot, dry, cold, and wet that would indicate the presence of one element more than another.
Its contribution was that he said that things are composed by something, what was wrong with this theory was that there are not elements there are atoms.
-Atoms= solid spheres indivisibles and indestructibles
1- Everything is made up of atoms
2- All atoms of a given element are the same and different from atoms of other elements.
3- Atoms of different element combine in a proportional way to form specific compounds.
4- Atoms are neither created nor destroyed, only transfomed.
> We now know that:
- atoms are made up of subatomic particles.
- atoms of the same element are not completely identical to each other.
All matter is made up small indestructible units he called atoms.Atoms are indestructible, also that they have no internal structure. His atomic model was solid, and stated all atoms differ in size, shape, mass, position and arrangement, with a void exists between them.
Experiment. What he did was take a simple seashell and break it in half. He then took that half and broke it in half over and over and over and over again until he was finally left with a fine powder. He then took the smallest piece from the powder and tried to break that but could not.Its contribution were the atoms and what was wrong with this model was that there is not complete there are missing particles.
"Plum Pudding model"
-He used te experiment of cathode rays: They were glass tubes that were electrified with a battery that polarizes the tube to have a negative charge end (cathode) and a positively charged end (anode). Rays were attracted to te positive charge so it must have a negative charge on it.
-It consisted on a shperically shaped atom composed by a uniformly distributed positive charge in which the individual negatively charged electrons resided
-An atom has the same number of electrons and protons, so it has no charge.
-it incorporated subatomic particles and new discoveries, such as the existence of the electron, and introduced the notion of the atom as a non-inert and divisible mass.
--This theory was refuted because Thomson's atomic model could not explain how the charge on the electrons inside the atom is maintained.The theory did not mention anything about the nucleus of the atom either.
"Nuclear atom model".
Atoms have small positive nucleus with electrons moving around.
Atoms are mostly empty space.
He bombarded a thin sheet of gold with positively charged particles (alpha particles were used) to see if they would pass straight through the foil as expected. However some particles bounced back from the foil or passed through at an angle (were deflected), suggesting the gold atoms were not a homogeneous mix of positive and negative.
"Solar system model" He postulated that electrons move around the nucleus in circular orbits.
Niels Bohr Atomic Theory:
Atoms are made up of 3 particles: electrons, protons and neutrons.
The protons and electrons are located on the center
Each energy level is associated with a fixed amount of energy.
"Quantum Model" or "Electron Cloud"
- Electrons are treated as waves.
- It can calculare the probability of finding an electronwithin a particular volume of space around the nucleus.
- The model assigns four quantum numbers to atomic orbitals.
- Shows electrons don´t move around the nucleus in orbits, but in clouds where their position is uncertain.
- Since this one is the most accurate model of the atom it doesn´t have anything wrong.
Friday, March 15th, 2019
Maria Fernanda Hernandez - 1945105
Yenci Carolina Rodriguez Salazar - 1974143
Andrea Carolina Berny Montaño - 1954450
Milena Andrea Zúñiga Cadena - 1946238
Sarahí Martínez Marroquín - 1955674
Liz Marín - 1952337
An atomic model is a conceptual diagram or structural representation of an atom, whose purpose is to explain its properties and functioning. In this case, about atoms