Section 4.2 Defining the atom. The Atom What we know now: Definition: Atoms are the smallest particle of an element that retains the properties of that.

Slides:

Advertisements

Similar presentations

Advertisements

An atom is made of a nucleus containing protons and neutrons; electrons move around the nucleus. Section 2: Defining the Atom K What I Know W What I Want.

Atomic Theory and the Atom

The Atomic Model Chem 9.

Chapter 4: Discovery of Atomic Structure. Prentice Hall © 2003Chapter 2 The Discovery of Atomic Structure An ancient Greek named Democritus was the first.

History of Atom Flip Book

Section 4.2 Defining the Atom.

CHAPTER 3: Atoms: The Building Blocks of Matter Section 2.

The Structure of an Atom

Atom : The smallest particle of an element that keeps all the properties of that element. Lesson: Old Dead Guys.

Evolution of the Atomic Theory. Greek Philosophy (400 BC) Democritus “All matter is made of atoms” Philosophy is knowledge gained only by observation.

The Atom - Scientists. Philosophers Democritus – believed matter was not infinitely divisible THERE WERE NO EXPERIMENTS TO TEST HIS IDEAS Matter is composed.

Subatomic Particles protons, neutrons and electrons.

Ch 5: Atomic Structure. warmup All matter is composed of very small particles called atoms. In middle school science you learned about the atom. 1. Draw.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 The Structure of the Atom Objectives Summarize the observed.

Do Now Determine the stationary object in the middle of the box without peaking in the box.

 Democritus (~400 BC) Greek philosopher who proposed that matter was made of tiny individual particles called “atomos” Believed atoms were indivisible.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Table of Contents Chapter 3 Atoms: The Building Blocks of Matter.

Ch. 3-2 Structure of the Nuclear Atom

Chapter 3: Atoms – The Building Blocks of Matter

Section 2: Defining the Atom

Atomic Structure.

Lecture 15 The Atom Ozgur Unal

Atomic Theory Label the 3 different particles that make up an atom

Do Now Determine the stationary object in the middle of the box without peaking in the box.

Structure of the Atom Chapter 4.

Origin of the idea of atom…

Atomic Structure Structure of the Nuclear Atom

Test 4: Chapter 4 – Atomic Structure

Chapter 5 Atomic Structure and the Periodic Table

Chapter 4: atoms.

Warm-Up Draw a picture of an atom. Be as specific as you can!

History of the Atomic Model 2.1

Section 2: Defining the Atom

Chapter 3 Lesson Starter

ATOMIC HISTORY & ISOTOPES

The Structure of the Atom

Chapter 3 Structure of the Atom

Matter and substance.

Origin of the idea of atom…

History of the Atomic Model 2.1

History of the Atomic Model 2.1

Chapter 3- Atomic Structure

History of the Atom.

The Structure of the Atom

Chapter 3 Experiments of Thomson and Millikan

Atomic Structure Ch. 4.

Atomic Structure.

Dalton’s Atomic Theory

Early Ideas About Matter

Research Hypothesis Theory An educated guess based on an observation

Early History of the Atom

History of the Atomic Model 2.1

4.1 & 4.2 Early Theories & Subatomic Particles

Chapter #3 Atoms: The Building Blocks of Matter Chapter 3A ATOMS:

An atom is made of a nucleus containing protons and neutrons; electrons move around the nucleus. Section 2: Defining the Atom K What I Know W What I Want.

Atomic Structure Chp 4.

CHAPTER 3 – The Structure of the Atom

Section Structure of the Nuclear Atom

You think you know, but do you???

Atomic Theory The idea that matter is made up of atoms, the smallest pieces of matter.

Chapter 3 Lesson Starter

Aim: What is the structure of the Atom?

Ch. 3-2 Structure of the Nuclear Atom

The Structure of the Atom

Presentation transcript:

Section 4.2 Defining the atom

The Atom What we know now: Definition: Atoms are the smallest particle of an element that retains the properties of that element.

Just how small is an atom? If atoms were the size of an orange, how big would an orange be?

New Model What we know: An atom is made of a nucleus containing protons and neutrons; electrons move around the nucleus. How have things changed since Dalton’s work?

Cathode Ray Tube AKA CRT Voltage source Cathode (-) Anode (+) - +

Cathode Ray Tubes Scientists discovered Cathode rays were a stream of charged particles Particles carry a negative charge Value of the charge was unknown Ray was produced no matter what material the cathode and anode were What can you conclude from the last point?

J. J. Thomson (1856 – 1940) Wanted to know more about electrons Electron – negatively charged particles found in all types of matter Experimented with CRTs to find the mass-to-charge ratio Found that the mass was much smaller than the mass of hydrogen What conclusion can we determine based on this finding? What did this change about Dalton’s theory?

Mass and Charge of the Electron J. J. Thomson determined the mass, but not the charge Robert Millikan (1868 – 1953) built on his work

Millikan’s Oil Drop Experiment What was the conclusion of these results?

Plum Pudding Model

The Nucleus Ernest Rutherford (1871 – 1937) Studied the interaction between charged alpha particles and solid matter

Rutherford’s Gold Foil Experiment: Expectations If you shot a cannon at a piece of tissue paper, what would you expect to happen?

Rutherford’s Gold Foil Experiment

Rutherford’s Gold Foil Experiment: Results Some deflected at a small angle Some deflected at a large angle Most passed through with little to no deflection What can we conclude from these results?

Rutherford’s Model of the Atom