ATOMIC STRUCTURE, NUCLEAR CHEMISTRY & UNIT 6

Slides:

Advertisements

Similar presentations

Atoms and their structure

Advertisements

How did different scientists contribute to atomic theory?

Atoms and their structure

Chapter 5 Atomic Structure and the Periodic Table

Atoms and their structure

Unit #3 Atomic Structure

Atoms, Molecules, and Ions

History of the Atom.

History of the Atomic Model

Early Models of the Atom –An atom is the smallest particle of an element that retains its identity in a chemical reaction. –Philosophers and scientists.

“Atomic Structure”. The Greek philosopher Democritus (460 B.C. – 370 B.C.) The Greek philosopher Democritus (460 B.C. – 370 B.C.) He believed that atoms.

Ancient Greece Democritus: .

Atomic Theory and the Atom

Atoms and their structure History of the atom n Not the history of atom, but the idea of the atom n Original idea Ancient Greece (400 B.C..) n Democritus.

History of the Atom; Modern Atomic Theory, Subatomic Particles

Chapter 4 Atoms and their structure History of the atom n Not the history of atom, but the idea of the atom. n Original idea Ancient Greece (400 B.C.)

Chapter 4 Atomic Structure Hingham High School Mr. Clune.

Atoms and their Structure History of the Atom n Original idea Ancient Greece (400 B.C..) n Democritus* and Leucippus: Greek philosophers.

Atomic Structure and The Periodic Table

Chapter 2 Atoms, Molecules, Ions.

End Show Slide 1 of 18 © Copyright Pearson Prentice Hall Defining the Atom > Early Models of the Atom An atom is the smallest particle of an element that.

History of Atomic Theory

Unit: Atomic Structure

PART ONE ATOMIC THEORY. Over the course of thousands of years our idea of what matter is made of and what the atom looks like has changed dramatically.

Chapter 4 Atoms and Their Structure History of the atom n Not the history of atom, but the idea of the atom n Original idea Ancient Greece (400 B.C..)

Models of the Atom: A Historical perspective

Atomic Structure Atoms and their structure Mr. Bruder.

Chapter 4 Atoms and their structure Early Theories of Matter (4.1) n Aristotle - Famous philosopher –All substances are made of 4 elements »Fire – Hot.

Chapter 4: Atomic Structure

The History of the Atom…. went against, Aristotle, who believed that matter was composed of four qualities: earth, fire, air and water all matter is composed.

History of Atomic Structure Atoms: their parts & pieces.

Chapter 4 Atoms and their structure History of the atom n Not the history of atom, but the idea of the atom n Original idea Ancient Greece (400 B.C..)

Chapter 4:Chemical Foundation Elements, Atoms, Ions.

Introduction to Atomic Structure Chemistry Chemistry is the study of matter and the changes it undergoes. The type of matter that is changing and what.

The Atom Chapter 4.

Chapter 2 (Part I) Atoms, Molecules, and Ions History n Greeks n Democritus and Leucippus - atomos n Aristotle- elements n Alchemy n Robert Boyle-

Chapter 3: The Atom “The Building Blocks of Matter”

Prior Knowledge Check n Who first came up with the idea of the atom? n What particles are found in atoms? n Where are these particles found?

Early Atomic Theory LG: I understand how the understanding of the atom has changed over time and the experiments that lead to these changes.

Atoms and their structure Labs n Labs are now online is a Google Docs folder n You can view the lab if you lose it (and you can copy and paste the procedure.

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

History of Atomic Structure Atoms and their parts.

Foundations of Atomic Theory The transformation of a substance or substances into one or more new substances is known as a chemical reaction.

Atoms and Their Structure Early Greek Theories 400 B.C. - Democritus crushed substances in400 B.C. - Democritus crushed substances in his mortar and.

The Atom Unit 3, Presentation 1. History of the atom Not the history of atom, but the idea of the atom – The atom was not “discovered” until recently.

The Structure of the Atom Chapter Early Theories of the Atom Subatomic Particles How Atoms Differ Unstable Nuclei & Radioactivity.

Atoms and their structure

1 The Structure of the Atom. 2 Early Theories of Matter.

John Dalton’s Atomic Theory  Elements composed of small particles called “atoms”  All atoms of a given element are the same, but different from other.

Chapter 3 Atoms and their structure History of the atom n Original idea Ancient Greece (400 B.C.) n Democritus and Leucippus- Greek philosophers. n Aristotle.

Atomic Structure Dalton’s Atomic Theory 1. All matter is made of tiny indivisible particles called atoms. 2. Atoms of the same element are identical,

Atoms and their structure History of the atom Original idea Ancient Greece (400 B.C..) Democritus Greek philosophers.

Chapter 3 Atoms: The Building Blocks of Matter. Lesson 1.1: Early Atomic Theory Learning Target: I will understand the history and structure of the atom.

Chapter 4. ◦ The lab technician shown here is using a magnifying lens to examine a bacterial culture in a petri dish. When scientists cannot see the details.

How did different scientists contribute to atomic theory?

Chapter 3 Atoms and their structure History of the atom n Democritus, a Greek philosopher, originally came up with the idea of an atom (around 400 BC)

Introduction to Atomic Theory. History of the atom Democritus (400 BC) suggested that the material world was made up of tiny, indivisible particles atomos,

Atomic Theory. Foundations of the Atomic Theory Foundations of the Atomic Theory Original idea Ancient Greece (400 B.C.) Democritus and Leucippus- Greek.

Atoms and their structure

Chapter 5 Atomic Structure and the Periodic Table

Atoms and their structure

Atoms and their structure

Atoms and their structure

Atomic Theory Models and Particles.

Atoms and their structure

Chapter 3 History.

Presentation transcript:

ATOMIC STRUCTURE, NUCLEAR CHEMISTRY & UNIT 6 What is an Atom? ATOMIC STRUCTURE, NUCLEAR CHEMISTRY & UNIT 6

Democritus He asked this question: If you break a piece of matter in half, and then break it in half again, how many breaks will you have to make before you can break it no further? Democritus thought that it ended at some point, a smallest possible bit of matter. He called these basic matter particles, atoms.

History of the Atom Aristotle – famous philosopher Believed all substances made of 4 elements Blending these in different proportions to get all substances Fire – hot air – light Earth – cool, heavy Water – wet

History of the Atom Late 1700s – John Dalton Teacher who summarized results of his experiments and those of others Combined idea of elements with that of atoms

Dalton’s Atomic Theory All matter is made of tiny, indivisible particles call atoms Atoms of the same element are identical Atoms of different elements combine in whole number ratios to form compounds Chemical reactions involve the rearrangement of atoms. No atoms are created or destroyed.

Atoms Smallest particle of an element that still retains the properties of that element

JJ Thompson In 1897, Thompson discovered the first component part of the atom: the electron, a particle with a negative electric charge. In 1904, he proposed an initial model of an atom, since nicknamed "Thompsons pudding". He imagined the atom as a sphere full of an electrically positive substance mixed with negative electrons "like the raisins in a cake".

Thomson’s Experiment Voltage source Vacuum tube Metal Disks

Thomson’s Experiment Voltage source - + Vacuum tube Metal Disks

Thomson’s Experiment Voltage source - +

Thomson’s Experiment Voltage source - +

Thomson’s Experiment Voltage source - +

- + Thomson’s Experiment Voltage source Passing an electric current makes a beam appear to move from the negative end to the positive end

- + Thomson’s Experiment Voltage source Passing an electric current makes a beam appear to move from the negative end to the positive end

- + Thomson’s Experiment Voltage source Passing an electric current makes a beam appear to move from the negative end to the positive end

- + Thomson’s Experiment Voltage source Passing an electric current makes a beam appear to move from the negative end to the positive end

Thomson’s Experiment Voltage source - + By adding an electric field…

- + Thomson’s Experiment Voltage source By adding an electric field… +

- + Thomson’s Experiment Voltage source By adding an electric field… +

- + Thomson’s Experiment Voltage source By adding an electric field he found that the moving pieces were negative

Millikan’s Experiment Atomizer Oil droplets - + Oil Telescope

Millikan’s Experiment X-rays X-rays give some electrons a charge.

Millikan’s Experiment From the mass of the drop and the charge on the plates, he calculated the mass of an electron

Other Particles Proton – positively charged pieces 1840 times heavier than electrons, discovered by E. Goldstein Neutron – no charge but the same mass as a proton, by J. Chadwick Where are these pieces?

Rutherford’s Experiment Ernest Rutherford – English physicist Believed in the plum pudding model of the atom

Rutherford’s Experiment Wanted to see how large the positive particles are Used radioactivity Shot alpha particles at gold foil Alpha particles – positively charged pieces,

Rutherford’s Experiment When an alpha particle hits a fluorescent screen it glows

Fluorescent Screen Lead block Uranium Gold Foil

Rutherford’s Experiment He expected the alpha particles to pass through without changing direction very much Because… The positive charges were thought to be spread out evenly Not enough to stop the alpha particles

What he expected

Because

He thought the mass was evenly distributed in the atom

Since he thought the mass was evenly distributed in the atom

What he got

How he explained it Atom is mostly empty. Small dense, positive piece at center. Alpha particles are deflected by it if they get close enough. +

+

Density and the Atom Since most of the particles went through, it was mostly empty space Because the alpha particles turned so much, the nucleus was heavy Small volume, big mass, big density The small dense positive area is the nucleus

The Nucleus

Structure of the Nuclear Atom Unit 6 – Part 2 Structure of the Nuclear Atom

Subatomic Particles Name Symbol Charge Relative Mass Actual Mass (g) Electron e- -1 1/1840 9.11 x 10-28 Proton p+ +1 1 1.67 x 10-24 Neutron n0

Counting the Pieces Atomic Number – the number of protons in the nucleus All protons are alike so… # of protons determines kind of atom The same as the number of electrons in a neutral atom

Counting the Pieces Mass number = # of protons + # of neutrons Protons and neutrons account for most of the mass of an atom

X Symbols Mass number Atomic number Contain the element symbol, mass number, and atomic number Mass number X Atomic number

F Symbols 19 9 Find: # of protons # of neutrons # of electrons Atomic # Mass # F 19 9

Br Symbols 80 35 Find: # of protons # of neutrons # of electrons Atomic # Mass # Br 80 35

Symbols If an element has 91 protons and 140 neutrons, what is the Atomic # Mass # # of electrons Complete symbol

Isotopes Dalton was wrong Atoms of the same element can have different numbers of neutrons This means different mass numbers Called isotopes

Naming Isotopes Can also put mass # after name of the element Carbon-12 Carbon-14 Uranium-235

Atomic Mass There are different kinds of oxygen atoms. More concerned with the average atomic mass

Atomic Mass Based on the abundance of each in nature Do not use grams because numbers would be too small

Measuring Atomic Mass Use the atomic mass unit (amu) One twelfth of a carbon-12 atom Each isotope has its own atomic mass Determine average from % abundance

Calculating Averages Multiply atomic mass by % abundance then add results

Atomic Mass - Example Calculate the atomic mass of copper if copper has two isotopes. 69.1% has a mass of 62.93 amu and the rest has a mass of 64.93 amu.

Atomic Mass – Example 2 Magnesium has 3 isotopes. 78.99% has a mass of 23.9850. 10.00% has a mass of 24.9858. The rest has a mass of 25.9826 amu. What is the atomic mass?

Atomic Mass Is not a whole number because it is an average The number on the periodic table