Development of Atomic Theory
DEVELOPMENT OF THE ATOMIC THEORY
Part A: HISTORY * 1869: Mendeleev formulated the Table of the Elements - listing them by their atomic weight and grouping them with similar characteristics. * 1897: JJ Thomson discovered electron and isotopes, and invented the mass spectrometer. * 1898: Marie Curie discovered and isolated radium, a new element which unprompted disintegrated into other elements. This proved that the atoms of one element at least were not indivisible. * 1911: Ernest Rutherford established that the nucleus was very dense, very small and positively charged. He also assumed that the electrons were located outside the nucleus. * 1922: Niels Bohr established his theory that the electrons travel in distinct orbits around the atom’s nucleus. * 1926: Erwin Schrodinger stated his development of the mathematical description that described the ways that electrons would follow in their orbits around the nucleus. * 1932: James Chadwick discovered the neutron that is no charge (neutral). He also found the neutron weighted slightly heavier than the proton. * 1939: Lisa Meitner published the first paper about nuclear fission. She predicted the existence of chain reaction, which contributed to the development of the atomic bomb later. * 1941: J Robert Oppenheimer was known as the “father of the nuclear bomb” after he was brought into the atomic bomb project of the US government. One year later he gathered the group of some of the best physicists in the country to discuss the design of the actual atomic bomb.
PART B: JOHN DALTON
In 1803, John Dalton proposed his atomic theory in which he stated that elements consisted of tiny particles called atoms. He also stated that the atom was simple, solid, and impenetrable and bond together in a specific proportion. He also said the reason elements differed from others was that atoms of each elements were different from one another, means that they have different masses.
He also
Part A: HISTORY * 1869: Mendeleev formulated the Table of the Elements - listing them by their atomic weight and grouping them with similar characteristics. * 1897: JJ Thomson discovered electron and isotopes, and invented the mass spectrometer. * 1898: Marie Curie discovered and isolated radium, a new element which unprompted disintegrated into other elements. This proved that the atoms of one element at least were not indivisible. * 1911: Ernest Rutherford established that the nucleus was very dense, very small and positively charged. He also assumed that the electrons were located outside the nucleus. * 1922: Niels Bohr established his theory that the electrons travel in distinct orbits around the atom’s nucleus. * 1926: Erwin Schrodinger stated his development of the mathematical description that described the ways that electrons would follow in their orbits around the nucleus. * 1932: James Chadwick discovered the neutron that is no charge (neutral). He also found the neutron weighted slightly heavier than the proton. * 1939: Lisa Meitner published the first paper about nuclear fission. She predicted the existence of chain reaction, which contributed to the development of the atomic bomb later. * 1941: J Robert Oppenheimer was known as the “father of the nuclear bomb” after he was brought into the atomic bomb project of the US government. One year later he gathered the group of some of the best physicists in the country to discuss the design of the actual atomic bomb.
PART B: JOHN DALTON
In 1803, John Dalton proposed his atomic theory in which he stated that elements consisted of tiny particles called atoms. He also stated that the atom was simple, solid, and impenetrable and bond together in a specific proportion. He also said the reason elements differed from others was that atoms of each elements were different from one another, means that they have different masses.
He also