Chapter 3 Atoms and Atomic Structure Write the bullets that are in black font.

Slides:

Advertisements

Similar presentations

Early Atomic Theory and the Structure of the Atom

Advertisements

History of the Atom.

Chapter 4 Atomic Structure

Atomic Theories.

Atomic Theory “History of. . . ”.

 You cannot see them, yet they make up everything…

History of Atomic Theory

Unit Six: Atomic structure

AIM: Models of the Atom DO NOW:

History of the Atom Model

Atomic Structure History of Atomic Theory. Democritus ( BC) Was the first person to come up with the idea of atom Believed that all matter was.

Chapter 4: Glow in the Dark

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

Atoms: The Building Blocks Of Matter

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.

Atomic Theory Chapter 3 Sections 1 &2 9/18/14.

The Development of the Atomic Theory

History of Atomic Theories Dr. Chin Chu River Dell Regional High School.

TITLE The Development of Atomic Theory. Early Ideas Democritus—Greece 400 B.C. His idea:  There was a limit to how far you could divide matter. You would.

 As early as 400 BC, a few people believed that atoms are the building blocks of all matter. Yet, until recently, even scientists had never seen evidence.

Atoms and Moles.  All matter is made of atoms  Law of definite proportions  Water is 88.8 % oxygen and 11.2 % hydrogen  Law of conservation of mass.

, 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.

Chapter 3 Atoms and Moles. Early Atomic theory 4 element theory Matter is made of atomos Alchemy Robert Boyle – proved water could be broken down; disproved.

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.

By: Andres Sanchez. Law Of Definite Proportions  Law of definite proportions states that two samples of a give compound are made of the same elements.

Atomic Structure. Way Early Theories Democritus ( BC) –First person to propose that matter is not infinitely divisible –Atomos –Matter is empty.

A History of Atomic Theory & Basic Atomic Structure Chapter 3: The Atom Big Idea: Physical, chemical and nuclear changes are explained using the location.

Section 1- Discovering the parts of the atom

Atomic Theory “History of... ”. The Ancient Greeks Democritus and other Ancient Greeks were the first to describe the atom around 400 B.C. The atom was.

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.

Ch.4 Atomic Structure How do we know atoms exist? Picture, in your mind, what you think an atom looks like.

Development of Atomic Structure How long have people been interested in understanding matter and its structure? A.Thousands of years B.Hundreds of years.

The Story of the Atom History and Other Early Stories.

Atoms, Molecules and Ions

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

HISTORY OF THE ATOM. Aristotle 400 BC 400 BC - Claimed that there was no smallest part of matter - Claimed that there was no smallest part of matter -

Chapter 4: Atomic Structure Democritus believed that matter was made up of particles. he called nature’s basic particle an “atom”. The …… Aristotle’s idea.

Atomic Theory 15,000 kilotons.  Dismissed idea of the atom. Early Greeks Two schools of thought:  Matter is made of indestructible particles called.

How long have people been interested in understanding matter and its structure? Thousands of years Hundreds of years A few years Never.

Atoms: The Building Blocks of Matter. PART 1  Democritus [400 B.C]  Greek philosopher  Hypothesized: Nature has a basic indivisible particle of which.

Friday October 1, 2010 (WS – ATOMIC STRUCTURE). Bell Ringer Friday, What do all atoms have in commom?

History of Atom Flip Book

In 1782, a French chemist, Antoine Lavoisier ( ), made measurements of chemical change in a sealed container. Development of the Modern Atomic.

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

Development of the atomic theory. Important laws Law of conservation of mass – Mass is neither created or destroyed during ordinary chemical reactions.

History of Atomic Theory from Democritus to Rutherford

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

EARLY ATOMIC THEORY CHAPTER 3. THE ATOM: FROM PHILOSOPHY TO SCIENTIFIC THEORY 400 BC – Democritus came up with the idea of the ________ Nature’s basic.

Atomic Structure.

Development of the atomic theory. Important laws Law of conservation of mass – Mass is neither created or destroyed during ordinary chemical reactions.

The History of the Atom. Aristotle  Aristotle was the first scientist that we have record of questioning what stuff was made of.  What did he think?

Chemistry What is chemistry? –Chemistry is the study of matter, what it is made of, and how it changes. What is matter? –Matter is anything that… Has.

Chapter 3 Atoms : The Building Blocks of Matter. Foundations of Atomic Theory  Several basic laws were after the 1790’s (emphasis on quantitative analysis):

+ ATOMIC THEORY. + Democritus Atom He was said to be the first step toward the current atomic theory. Hypothesized all matter is composed of tiny particles.

The Beginning of the Atomic Theory Democritus was a Greek philosopher who was among the first to suggest the existence of atoms. 460 BC – 370 BC.

Atomic Models. Atomic Theories Atomic Theory – A Short History  Fifth Century, BCE  Democritus  Believed matter was composed of very small, individual.

Foundations of the Atomic Theory. Don’t forget how we got here, thanks to Democ., Aristotle, and the Particle Theory of Matter.

Chemistry Chapter Three – Atoms: The Building Blocks of Matter South Lake High School Science Department Ms. Sanders.

Chapter 3: Atoms and Moles Sections 1 and 2

Atomic Theory & Periodic Table Unit 3 Part 1 (Ch. 4 & 5) Atomic Theory Introduction, Isotopes.

Atomic Theory In 1808, the English Chemist John Dalton proposed the first theory of the nature of matter in stating that all matter was composed of atoms.

Goal 5.01 Atomic Theory. Basic Laws of Chemistry Law of conservation of massLaw of conservation of mass: mass is neither created or destroyed during chemical.

Chapter 3: Discovering the Atom and Subatomic Particles

Chapter 3 Atoms and Moles

BELLWORK 9/11/17 What is the atom?

Presentation transcript:

Chapter 3 Atoms and Atomic Structure Write the bullets that are in black font.

Atomic Theories l The idea of an atomic theory is more than 2000 years old. l Until recently, scientists had never seen evidence of atoms. These theories were made BEFORE knowing the parts of an atom. l The law of definite proportions, the law of conservation of mass and the law of multiple proportions support the current atomic theory.

1. The Law of definite proportions l a chemical compound always contains the same elements in exactly the same proportions by weight or mass. l every molecule of a substance is made of the same number and types of atoms. l Ex: H 2 O is water, H 2 O 2 is not. l (Goes back to the idea that compounds are pure substances and have a definite composition)

2. Law of Conservation of Mass l mass cannot be created nor destroyed; it just changes form. l The mass of the reactants is equal to the mass of the products.

3. Law of Multiple Proportions l Elements always combine in whole number ratios when compounds are formed. l Ex: H 2 O, not HO 1/2

Dalton’s Atomic Theory l In 1808, John Dalton developed an atomic theory. l Dalton believed that a few kinds of atoms made up all matter. l According to Dalton, elements are composed of only one kind of atom and compounds are made from two or more kinds of atoms. l His theory contains five principles.

Dalton’s five principles 1. All matter is composed of extremely small particles called atoms, which cannot be subdivided, created, or destroyed. 2. Atoms of a given element are identical in their physical and chemical properties. 3. Atoms of different elements differ in their physical and chemical properties. 4. Atoms of different elements combine in simple, whole-number ratios to form compounds. 5. In chemical reactions, atoms are combined, separated, or rearranged but never created, destroyed, or changed. l Data gathered since Dalton’s time shows that the first two principles are not true in all cases, and the next three were already hypothesized.

Parts of the Atom l Experiments by several scientists in the mid-1800s led to the first change to Dalton’s atomic theory. Scientists discovered that atoms can be broken into pieces after all. l The smaller parts that make up atoms are called subatomic particles. l The three subatomic particles that are most important for chemistry are the electron, the proton, and the neutron.

1. Electrons J.J. Thomson used a cathode ray tube: air was pumped out of a glass tube to make a vacuum. Electrodes were placed at either end of the tube. A glowing beam was produced. Beam was attracted to the positive end of a magnet, and repelled by the negative end. Therefore, the beam must be negatively charged = electrons.

Cathode ray tube

Thomson also observed that when a small paddle wheel was placed in the path of the rays, the wheel would turn.  Beam must be composed of particles because the wheel turned.

l Thomson realized that electrons are negatively charged, but atoms have no charge. Therefore, atoms must contain some positive charges that balance the negative charges of the electrons. This lead to the search for protons.

Protons and the nucleus Ernest Rutherford performed the gold foil experiment. A beam of small, positively charged particles was directed at a thin gold foil. Rutherford found that most of the alpha particles shot at the foil passed straight through the foil = nucleus is very small and dense. Some (very few) were deflected back = nucleus must contain positive particles. (like charges repel)

Gold foil experiment

Neutrons Chadwick: Neutrons are the subatomic particles that have no charge and that is found in the nucleus of an atom.

Atomic Models Thomson : electrons are embedded in a positively charged ball of matter. His model was named the plum-pudding model. (Mrs. C: Chocolate chip cookie model)

Rutherford  Electrons revolved around the nucleus.  Rutherford’s model could not explain why electrons did not crash into the nucleus.

Bohr Electrons travel around in the nucleus in specific energy levels. Electrons that are close to the nucleus are in their lowest energy level. “Jimmy Neutron” model

Current model: Electron Cloud electrons are located in orbitals, regions around a nucleus that correspond to specific energy levels. Orbitals are regions where electrons are likely to be found.