The History of the Atomic Theory. Democritus 300 BC Atom the indivisible; cannot be further broken...

The History of the The History of the Atomic TheoryAtomic Theory

DemocritusDemocritus

• 300 BC

• Atom the indivisible; cannot be further broken down into smaller pieces".

• The atom as the smallest particle of matter.

Dalton Dalton c.1800 c.1800

- Atoms are seen as solid, indestructible - Atoms are seen as solid, indestructible spheres (like billiard balls) spheres (like billiard balls)

- Explains how atoms combine - Explains how atoms combine to form molecules.to form molecules.

- Confirms basic Laws of Chemistry: - Confirms basic Laws of Chemistry: “ “Conservation of Mass andConservation of Mass and Definite Proportions”.Definite Proportions”.

JJ ThomsonJJ Thomson

• C. 1850

• Chocolate chip cookie model : Chocolate chip cookie model :

• Atoms are solid spheres made-up of a Atoms are solid spheres made-up of a solid positive mass (or core) with tiny solid positive mass (or core) with tiny negative particles embedded in the negative particles embedded in the positive core.positive core.

RutherfordRutherford• 1905 • Famous Gold Leaf Experiment.Famous Gold Leaf Experiment.• Proved the atom is mostly made of empty Proved the atom is mostly made of empty

space.space.

• Proved that the nucleus is Proved that the nucleus is positive and the electrons are positive and the electrons are outside the nucleus.outside the nucleus.

BohrBohr• 1920

• Electrons in definite energy levels Electrons in definite energy levels around the nucleus.around the nucleus.

• Proved that electrons are placed in Proved that electrons are placed in definite energy levels (called Orbitals) definite energy levels (called Orbitals) around the nucleus.around the nucleus.

• Speaks of Neutrons in the nucleusSpeaks of Neutrons in the nucleus

* 2, 8, 8, 2 ** 2, 8, 8, 2 *

Atomic Review Video

Main Principles:Main Principles:

- All matter is made up of tiny particles called - All matter is made up of tiny particles called atoms.atoms.

- Atoms are made of even smaller particles: Atoms are made of even smaller particles: Protons (+), Electrons (-), and Neutrons (o)Protons (+), Electrons (-), and Neutrons (o)

- Atoms can be distinguished from each Atoms can be distinguished from each other by their number of protons, electrons other by their number of protons, electrons and neutrons.and neutrons.

Periodic Table of ElementsPeriodic Table of Elements

What the heck does it mean?What the heck does it mean?

Each element is broken down the same way.Each element is broken down the same way.

The History of the Atomic Theory. Democritus 300 BC Atom the indivisible; cannot be further broken...

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Transcript of The History of the Atomic Theory. Democritus 300 BC Atom the indivisible; cannot be further broken...

Development of Atomic Theory 400 B.C. -Democritus was first to use the word : atom atomos meaning “indivisible” Aristotle (famous philosopher) disputed.

Atom – the smallest unit of matter “indivisible”

The Atom Chapter 3. From Idea to Theory Democritus, Greek philosopher, 400 B.C., introduced the concept of an atom, an ‘indivisible’ particle. Democritus,

Unit 3 History of the Atom. Democritus about 400 b.c. stated that the “ultimate particle” is atmos He believed that atoms were indivisible and indestructible.

THE STRUCTURE OF THE ATOM ATOMIC MODELS PIONEERS OF THE ATOM DEMOCRITUS LAVOISIER DALTON THOMPSON MILLIKEN RUTHERFORD DEMOCRITUS LAVOISIER DALTON THOMPSON.

The History of Atomic Structure. Democritus Named the atom from the Greek word “atomos” meaning indivisible. Wrote that atoms were the smallest unit.

Chapter 6 Atomic Theory. Greek Idea Democritus –Matter is made up of indivisible particles Dalton –One type of atom for each element.

The Atom Chapters 4-5 Atomic Theories Democritus ~ 400 BC believed that atoms were indivisible and indestructible Dalton ~ 1800’s Developed through experiments.

Ch. 4: Atomic Structure 4.1 Defining the Atom. History Democritus named the most basic particle named the most basic particle atom- means “indivisible”

Atomic Discovery Early Models of the Atom 400 B.C. – Democritus proposed the existence of fundamental particles of matter that were indivisible and indestructible.

Chemical Bonds Atom – the smallest unit of matter indivisible Helium atom.

History of the Atom Model 450 BC Democritus (Greek)- World was made of 2 things: 1.Empty space 2.Tiny particles call atoms (Atomus= indivisible) Aristotle.

ATOMIC PHYSICS Early Atomic Theory 1.Democritus 440BC The smallest indivisible particle of matter is the atom. 2.Aristotle 340BC criticised an alternative.

The Atom. Basic Atomic Theory Atom = “indivisible” in Greek Atoms are indivisible and indestructible Atoms of same element are identical Compounds.

, who was from was the first person to use the term atom during B.C. Democritus defined the atom as being. opposed Democritus because believed that.

Electrons in Atoms. Models of the Atom Atoms are the smallest indivisible part of an element—who stated this? John Dalton (thanks to Democritus) The atom.

Go to section Chapter 4 Atomic Structure. Go to section History of Atom Democritus (2500 YEARS AGO) Greek philosopher –Atmos – “uncut” or “indivisible”

1. Review of Ancient Models of Matter Leucippus and Democritus - the idea of the “atom” – the indivisible particle Empedocles and Aristotle - the 4- element.

Atomic Timeline A History of the Atom. Democritus 460 BC Matter is composed of indivisible units These particles he described by using the Greek word.

Atom – the smallest unit of matter “indivisible” Helium atom.