Chapter 19 – Chapter 19 – Properties of Atoms Properties of Atoms and the Periodic and the Periodic tabletable19.1 – Structure of the Atom19.1 – Structure of the Atom

Guided Notes Page

Objectives - 1-4Objectives - 1-4

Identify the names and symbols of Identify the names and symbols of common elements.common elements.

Describe characteristics and location of Describe characteristics and location of atomic particles. (Composition and charge)atomic particles. (Composition and charge)

Describe the electron cloud model of the Describe the electron cloud model of the atom.atom.

Explain how electrons are arranged in an Explain how electrons are arranged in an atom.atom.

Scientific ShorthandScientific Shorthand

Chemical symbols Chemical symbols = used to = used to abbreviate the abbreviate the name of an elementname of an element

Accepted and used Accepted and used worldwideworldwide

http://www.ptable.com/

One capital letter or one capital letter and One capital letter or one capital letter and 1-2 lowercase letters1-2 lowercase letters

Some are simply the 1Some are simply the 1stst (or 1 (or 1stst and and another letter) of the element’s nameanother letter) of the element’s name H = HydrogenH = Hydrogen Ca = CalciumCa = Calcium

Others are derived from the Latin name Others are derived from the Latin name of the elementof the element Ag = SilverAg = Silver Fe = IronFe = Iron

Latin namesLatin names

Cu – Cuprum (Copper)Cu – Cuprum (Copper) Au – Aurum (Gold)Au – Aurum (Gold) Fe – Ferrum (Iron)Fe – Ferrum (Iron) Pb – Plumbum (Lead)Pb – Plumbum (Lead) Hg – Hydrargyum (Mercury)Hg – Hydrargyum (Mercury) K – Kalium (Potassium)K – Kalium (Potassium) Ag – Argentum (Silver)Ag – Argentum (Silver) Na – Nathum (Sodium)Na – Nathum (Sodium) W – Wolfram (Tungsten)W – Wolfram (Tungsten)

Atomic ComponentsAtomic Components

Atom = smallest piece of matter that Atom = smallest piece of matter that retains properties of the elementretains properties of the element

Atomic ParticlesAtomic Particles Protons (p+) = positive charged particlesProtons (p+) = positive charged particles Neutrons (nNeutrons (noo) = uncharged particles) = uncharged particles Electrons (eElectrons (e--)= negative charged particles)= negative charged particles

Protons and Neutrons are found in the Protons and Neutrons are found in the nucleus of an atomnucleus of an atom

QuarksQuarks

Scientists confirm that p+ & nScientists confirm that p+ & noo are made are made of smaller particles called Quarksof smaller particles called Quarks

6 uniquely different quarks6 uniquely different quarks Arrangement of 3 = protonArrangement of 3 = proton Different arrangement of 3 = neutronDifferent arrangement of 3 = neutron

Atomic ModelAtomic Model

400 B.C. – Democritus 400 B.C. – Democritus proposed the idea that atoms proposed the idea that atoms make up all substancesmake up all substances Aristotle disputed Democritus' Aristotle disputed Democritus'

theory theory and said matter was and said matter was uniform throughout and not uniform throughout and not composed of smaller particlescomposed of smaller particles

Aristotle had more clout and his Aristotle had more clout and his theory held for more than 2000 theory held for more than 2000 yearsyears

http://faculty.washington.edu/smcohen/320/Democritus.jpg

http://academic.shu.edu/honors/aristotle.jpg

Atomic ModelAtomic Model

1800s – John Dalton 1800s – John Dalton was able to prove was able to prove atoms existatoms exist Solid sphere = atomSolid sphere = atom Provided physical Provided physical

explanation for chemical explanation for chemical reactionsreactions

Atomic ModelAtomic Model

1904 – J.J. Thomson said 1904 – J.J. Thomson said electrons were found electrons were found throughout positive spherethroughout positive sphere

1911 – Ernest Rutherford 1911 – Ernest Rutherford said atoms was not a said atoms was not a sphere but rather a central sphere but rather a central mass (nucleus) mass (nucleus) surrounded by electronssurrounded by electrons

http://wind.cc.whecn.edu/~mechalke/chapter5/Thomson.gif

http://www.cfo.doe.gov/me70/manhattan/images/AtomLabeled.gif

Atomic ModelAtomic Model

1913 – Niels Bohr said electrons move in 1913 – Niels Bohr said electrons move in fixed orbitsfixed orbits

http://www.green-planet-solar-energy.com/images/bohr_atom.gif

Atomic Model - currentAtomic Model - current Electron Cloud Model Electron Cloud Model

= area around nucleus = area around nucleus where electron likely to where electron likely to be foundbe found

Electrons move so Electrons move so quickly it is difficult to quickly it is difficult to pinpoint exact locationpinpoint exact location

Electrons do not follow a Electrons do not follow a rigid pattern of rigid pattern of movementmovement

In-Class In-Class Assignment/HomeworkAssignment/Homework

19.1 Reinforcement WKT19.1 Reinforcement WKT

Modeling an Aluminum Modeling an Aluminum AtomAtom Gather 13 blue dots, 13 green dots and 14 red dotsGather 13 blue dots, 13 green dots and 14 red dots Arrange all blue dots and all red dots on a flat Arrange all blue dots and all red dots on a flat

surface to represent the nucleus of an atomsurface to represent the nucleus of an atom Each blue dot = protonEach blue dot = proton Each red dot = neutronEach red dot = neutron

Position 2 green dots 2 cm from the nucleusPosition 2 green dots 2 cm from the nucleus Position 8 green dots 5 cm from the nucleusPosition 8 green dots 5 cm from the nucleus Position 3 green dots 8 cm from the nucleusPosition 3 green dots 8 cm from the nucleus

Answer questions from pg. 581 on back Answer questions from pg. 581 on back of paperof paper