Evolution of Atoms Flashcards
Just the men behind the discovery of atom (excluding the dates)
“Matter could not be divided indefinitely”
Democritus
He named the smallest piece of matter “atomos” meaning “not to be cut” or “indivisible”
Democritus
“Atoms were small, hard particles that were all made of the same material but were different shapes and sizes”
Democritus
He believed that matter could be divided into smaller and smaller pieces forever
Aristotle
He believed that matter was made of a combination of four elements: earth, fire, water, and air
Aristotle
He proposed the hook and eye model (to account for chemical combination) based on experimentation and not on pure reason
John Dalton
He proposed the atomic theory by studying gases
John Dalton
He was the one who first proposed that atoms are divisible.
J.J. Thomson
He found that atoms could sometimes eject a far smaller negative particle, the electron (1897) while working with a cathode ray tube.
J.J. Thomson
He called the negatively charged particle “corpuscles”, today known as electrons
J.J. Thomson
He developed the Plum Pudding model of an atom
J.J. Thomson
TRUE or FALSE: The plums represented the negative electric charges (electrons), and the pudding as a shapeless mass of uniform positive electrification
True
He introduced that the positive electrification mentioned by Thomson is a small dense center he named nucleus (1911)
Ernest Rutherford
He is considered to be the father of nuclear physics.
Ernest Rutherford
He also discovered the proton (1919)
Ernest Rutherford
The Nuclear Model of Atom is made by
Ernest Rutherford
This model is described wherein the atom contains a small, dense, positively-charged center (nucleus), with negative electrons orbiting a nucleus in set, predictable paths
The Nuclear Model of Atom
A Danish scientist who proposed an improvement by placing each electron in a specific energy level.
Niels Bohr
He also proposed that electrons can move up a level if given enough energy. He called this energy a quantum of an energy and the movement of electron a quantum leap.
Niels Bohr
He proposed the Planetary Model of Atom
Niels Bohr
According to him, electrons move in definite orbits around the nucleus much like planets circle the sun.
Niels Bohr
An Austrian physicist who used mathematical equations to describe the likelihood of finding an electron in a certain position, with the help of Werner Heisenberhg
Erwin Schrodinger
Erwin Schrodinger developed a model known as?
Electron cloud model, also called as Quantum mechanical model
He introduced the concept of sub-energy levels (s, p, d, f)
Erwin Schrodinger
This model can be portrayed as a nucleus surrounded by an electron cloud
Quantum Mechanical Model of Atom
He discovered neutron in 1932 while experimenting on the radiation emitted by Beryllium
James Chadwick
He also described that neutron is slightly heavier than proton and could penetrate much further into a target than protons
James Chadwick
He was awarded a Nobel Prize in Physics in 1935 for his discovery of neutron
James Chadwick
TRUE or FALSE: Neutron took longer time to be discovered because neutron has no charge.
True
