SCIENCE HISTORY OF ATOMS

A brilliant German Physicist, modified Niels Bohr's atomic theory to include elliptical orbits. Electrons are moving around the nucleus.

Arnold Sommerfeld

Democritus named the smallest piece of matter: "_________" meaning "not to be cut".

Atomos

In 1908, an English Physicist, was hand at work on an experiment.

Ernest Rutherford

A Physicist and a Biologist, was considered the Father of Quantum Mechanics. Today's atomic model is based on the principles of wave mechanics. Electrons do not move around an atom in a definite path like the planets around the sun.

Erwin Schrodinger

Democritus

He is a Greek Philosopher who began to search for a description of matter.

In the early 1800s, an English Chemist performed a number of experiments that eventually led to the acceptance of the idea of atoms. He deduced that all elements are composed of atoms.

John Dalton

In 1897, an English Scientist, provided the first hint that an atom is made of even smaller particles.

Joseph John Thomson

In 1913, a Danish Scientist, proposed an improvement. He placed each electron in an specific energy level.

Niels Bohr

Electrons move in definite orbit around the nucleus much like planet circles the sun.

Orbit

Joseph John Thomson proposed a model of the atom that is sometimes called

Plum Pudding Model

What is an atom?

The smallest particle of an element.

What is the definition of Democritus' Atomic model called "Atomos"

They were small, hard particles that were all made of the same material but were different shapes and sizes.

What is this model called?

This piece is indivisible

Joseph John Thomson introduced the idea about the negatively charged particle called

electron

Ernest Rutherford reasoned that all atoms that are positively charged particles were contained in the

nucleus