The Begenius School The Begenius School of Atom Model of Atom Model

DrawingDrawing

Everything you wanted to Everything you wanted to know to pass your next quiz know to pass your next quiz

on atomson atoms

People, Theories, and People, Theories, and ModelsModels

DemocritusDemocritus – ancient Greek – ancient Greek that named the atom after that named the atom after “atomos” which means “atomos” which means indivisible.indivisible.

AristotleAristotle argued against this argued against this idea suggesting that matter idea suggesting that matter could be divided infinitely.could be divided infinitely.

John DaltonJohn Dalton – first – first chemistchemist that made the first table of that made the first table of elements and was the first to elements and was the first to suggest that atoms of gold were suggest that atoms of gold were unique and different from atoms unique and different from atoms of iron. He had a theory called of iron. He had a theory called the billiard ball model of the billiard ball model of atoms…suggesting that atoms atoms…suggesting that atoms were like balls that collide with were like balls that collide with each other and have unique each other and have unique masses and properties.masses and properties.

Dalton proved inDalton proved in 1802 1802 that that atoms were real and he atoms were real and he pictured them as small billiard pictured them as small billiard balls. He used an example that balls. He used an example that if you had some gold each atom if you had some gold each atom would be solid gold. would be solid gold.

More about People, Theories, More about People, Theories, and Modelsand Models

In1897 In1897 J.J. ThomsonJ.J. Thomson published a theory published a theory called the called the Plum Plum Pudding ModelPudding Model of an of an atom.atom.

His model put the first His model put the first electrical quantities into electrical quantities into the model called the model called electrons.electrons.

The electrons were seen The electrons were seen as negative charges and as negative charges and the pudding part of the the pudding part of the model was seen as a model was seen as a positively charged positively charged material making up the material making up the rest of the atom.rest of the atom.

Plum Pudding Model

Even more about people, Even more about people, theories and modelstheories and models

In 1911 Ernest In 1911 Ernest Rutherford disproved Rutherford disproved the plum pudding the plum pudding model by proving the model by proving the existence of a nucleus existence of a nucleus which held most of the which held most of the mass and an empty mass and an empty space between the space between the nucleus and the orbits nucleus and the orbits of electrons.of electrons.

Eventually this grew Eventually this grew into our model that has into our model that has protons and neutrons in protons and neutrons in the nucleus and the nucleus and electrons in orbits electrons in orbits spinning around the spinning around the nucleus.nucleus.

Final notes about people, Final notes about people, theories and modelstheories and models

Niels Bohr applied Niels Bohr applied quantum physics to quantum physics to the model of the atom the model of the atom in 1913 and added a in 1913 and added a specific orbital/energy specific orbital/energy level concept to the level concept to the atom.atom.

Each atom is now Each atom is now seen as having a seen as having a specific pattern of specific pattern of space where electrons space where electrons can be found called s, can be found called s, p, d, and f orbitals.p, d, and f orbitals.

Final notes about people, Final notes about people, theories and modelstheories and models

The electron cloud model The electron cloud model puts all of the parts of the puts all of the parts of the atom into high speed motion, atom into high speed motion, and suggest that we never and suggest that we never really know exactly where really know exactly where electrons will be but that electrons will be but that there are regions where we there are regions where we may find them.may find them.

Erwin Schrodinger is credited Erwin Schrodinger is credited with the cloud model. with the cloud model.

The cloud model represents a The cloud model represents a sort of history of where the sort of history of where the electron has probably been electron has probably been and where it is likely to be and where it is likely to be going.  The red dot in the going.  The red dot in the middle represents the nucleus middle represents the nucleus while the red dot around the while the red dot around the outside represents an outside represents an instance of the electron.  instance of the electron.  Imagine, as the electron Imagine, as the electron moves it leaves a trace of moves it leaves a trace of where it was.   This collection where it was.   This collection of traces quickly begins to of traces quickly begins to resemble a cloud.  resemble a cloud. 

How to Draw an AtomHow to Draw an Atom First step is to find the element on the periodic First step is to find the element on the periodic

table.table. Which row or period is it in? This tell you how Which row or period is it in? This tell you how

many orbitals it has.many orbitals it has. What is its atomic number? This tells you the What is its atomic number? This tells you the

number of protons and electrons it has.number of protons and electrons it has. What is the atomic mass (weight)? Round it off What is the atomic mass (weight)? Round it off

and subtract the atomic number and you have and subtract the atomic number and you have found the number of neutrons.found the number of neutrons.

Record these answers in a table Record these answers in a table like thislike this

Check out an example.Check out an example. OO PP EE NN

22 55 55 66

OO PP EE NN

+++

++o

o oo

oo

-

- -

-

- ?

?

?

?

?-hold places in orbitals that could have an electron but do not have one

?

Try to draw carbon, and Try to draw carbon, and oxygen and see how you do.oxygen and see how you do.

Ask Mr. Manning when you return to Ask Mr. Manning when you return to class on Wednesday for help if you class on Wednesday for help if you do not understand.do not understand.

Try the review slides that follow.Try the review slides that follow.

ReviewReview This ancient Greek named the atom.This ancient Greek named the atom.

DemocritusDemocritus This Greek argued against the existence of atoms.This Greek argued against the existence of atoms.

AristotleAristotle He was the first chemist and made the first table of He was the first chemist and made the first table of

elementselementsJohn DaltonJohn Dalton

In 1897 he published the Plum Pudding Model which put the In 1897 he published the Plum Pudding Model which put the electron into the atom.electron into the atom.J.J. ThomsonJ.J. Thomson

He put the nucleus into the atom modelHe put the nucleus into the atom modelErnest RutherfordErnest Rutherford

He put the specific regions of electrons called orbitals into He put the specific regions of electrons called orbitals into the model.the model.Niels BohrNiels Bohr

He helped develop the electron Cloud model.He helped develop the electron Cloud model.Erwin SchrodingerErwin Schrodinger

Review ContinuedReview Continued The particle with a positive charge in the nucleus of the atomThe particle with a positive charge in the nucleus of the atom

ProtonProton The particle in the nucleus of the atom with no chargeThe particle in the nucleus of the atom with no charge

NeutronNeutron The particle with a negative charge that spins at high speed The particle with a negative charge that spins at high speed

around the nucleus of the atomaround the nucleus of the atomElectronElectron

Particles numbers that are the same as the atomic numberParticles numbers that are the same as the atomic numberProtons and electronsProtons and electrons

Particle number the same as the atomic mass or weightParticle number the same as the atomic mass or weightNoneNone

Particle number found by subtracting the atomic number from the Particle number found by subtracting the atomic number from the atomic mass whole number partatomic mass whole number partNeutronNeutron

The atomic structure number found by the row or period on which The atomic structure number found by the row or period on which an element is foundan element is foundNumber of orbitalsNumber of orbitals

The symbol used to represent spaces in an atom where electrons The symbol used to represent spaces in an atom where electrons could be found but are not foundcould be found but are not foundQuestion markQuestion mark