Atoms and Molecules By Doba Jackson, Ph.D.. Outline of Concepts in this chapter Law of Constant Composition (sec. 2-4) –Mass Percentages Dalton’s Atomic.

Slides:

Advertisements

Similar presentations

The Structure of the Atom

Advertisements

Have 1 Periodic Table per group!.  The mass number.

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.

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

» What is the name of this device? » Which scientist used this device?

Chapter 5: Atomic Theory: The Nuclear Model of the Atom

Atoms and Atomic Theory Chapter Early Chemical Discoveries and the Atomic Theory.

Chapter Two: Atoms, Molecules and Ions

C142 B (Campbell / Callis) Chapter 2: The Components of Matter 2.1: Elements, Compounds, and Mixtures: An Atomic Overview 2.2: The Observations That Led.

Christopher G. Hamaker, Illinois State University, Normal IL

Atomic Mass and the Mole. Relative Atomic Mass Units of grams are TOO LARGE for atoms! Relative atomic mass – compare to small particles – amu – “atomic.

Chapter 2 Atoms, molecules, and ions

C H E M I S T R Y Chapter 2 Atoms, Molecules, and Ions.

THE BUILDING BLOCKS OF MATTER

Unit 3 Language of Chemistry Part 1 Zumdahl: Chapter 4 Holt: Chapter 3.

Chemistry Chapter 3 Review Game. ChemistryChemistry Chemistry 1 point 1 point 1 point 1 point 1 point 1 point 1 point 1 point 2 points 2 points 2 points.

John E. McMurry Robert C. Fay C H E M I S T R Y Sixth Edition Chapter 2 Atoms, Molecules, and Ions.

Lecture Notes Alan D. Earhart Southeast Community College Lincoln, NE Chapter 2 Atoms, Molecules, and Ions John E. McMurry Robert C. Fay CHEMISTRY Fifth.

AP Chemistry – Chapter 2 Atoms, Molecules and 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.

Chapter 1 Atomic Structure 1.1 The Atomic Nature of Matter

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

Chapter 4: Atomic Structure

Atomic Structure.

Chapter 4: Atomic Structure

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

C H E M I S T R Y Chapter 2 Atoms, Molecules, and Ions.

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

Atoms, Molecules and Ions

Chapter 3 Atoms: The Building Blocks of Matter. The Atomic Theory  Law of conservation of mass  Mass is neither destroyed nor created  Law of definite.

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.

Chapter 3 Atoms and Elements 3.4 The Atom 1. The Law of Multiple Proportions and Dalton’s Atomic Theory Elements are made up of tiny particles called.

Lecture 3, Fall CHAPTER 2. Atoms, molecules, and ions.

Atoms, Molecules, and Ions Chapter 2 Atoms, Molecules, and Ions John D. Bookstaver St. Charles Community College St. Peters, MO  2006, Prentice Hall,

Atomic Structure. 1. Democritus: Around 300 BC, a Greek philosopher, Democritus stated that everything is made up of tiny, invisible particles He said.

The Modern Nuclear Atom How did our concept of the atom come about, and how did it develop?

Chapter 3 pages Modern Chemistry Chapter 3 Atoms: the building block of matter.

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

John E. McMurry Robert C. Fay Lecture Notes Alan D. Earhart Southeast Community College Lincoln, NE General Chemistry: Atoms First Chapter 2 The Structure.

The Atom Chapter 3. From Idea to Theory Democritus, Greek philosopher, 400 B.C., introduced the concept of an atom, an ‘indivisible’ particle. Democritus,

CHM 109 SUROVIEC FALL 2015 Atoms and Elements. I. Atoms and Atomic Theory An element is composed of tiny particles called atoms  All atoms of the same.

Chapter 5 Atomic Structure & the Periodic Table. Sec 1: Atoms Democritus was the first to suggest the idea of atoms. The modern idea of the atom started.

Ch. 4: Atoms/Atomic Theory. Atoms Definition - the smallest particle that has the properties of an element, basic unit of matter 119 distinct atoms as.

Atomic Structure Chapter 4. Dalton’s Atomic Theory 4.1 John Dalton – 18 th century All matter is composed of atoms All atoms of a given element are identical.

The Atom. Dalton’s Atomic Theory 1.Elements are made of tiny particles called atoms. 2.All atoms of a given element are identical. 3.The atoms of a given.

Ariana Garcia-Minsal. Dalton's Atomic Theory - (1808) His atomic theory could be summarized as: 1)Matter is composed of tiny and indivisible particles.

ATOMS: The Building Blocks of Matter Objectives 1.Law of conservation of mass 2.Law of definite proportions 3.Law of multiple proportions 4.Dalton’s Atomic.

Chapter 3 Atoms: The Building Blocks of Matter. Sect. 3-1: The Atom: From Philosophical Idea to Scientific Theory  Democritus vs. Aristotle  Atom vs.

Chemistry – King William High School.  Foundations…  Law of conservation of mass – mass is neither created nor destroyed  Law of definite proportions.

1 Modern Chemistry Chapter 3 Atoms: The Building Block of Matter.

Ch. 3 Atoms: The Building Blocks of Matter. Table of Contents Chapter 3 Atoms: The Building Blocks of Matter Section 1 The Atom: From Philosophical Idea.

John E. McMurry Robert C. Fay C H E M I S T R Y Sixth Edition © 2012 Pearson Education, Inc. Chapter 2 Atoms, Molecules, and Ions.

Chapter 2 Atoms, Molecules and Ions. Conservation of Mass and the Law of Definite Proportions Law of Conservation of Mass: Mass is neither created nor.

Atoms CHAPTER 4. Democritus develops the idea of atoms 460 B.C. he pounded up materials until he had reduced them to smaller and smaller particles which.

Smallest particle of an element that retains the properties of the element.

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

Atomic Structure CHAPTER 4. Defining the Atom ✴ An atom is the smallest particle of an element that still has the chemical properties of that element.

History of the Atom. Atoms and Elements Any material that is composed of only one type of atom is called an element. An atom is the smallest particle.

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

C H E M I S T R Y Chapter 2 Atoms, Molecules, and Ions.

1 UNIT 2 Atoms, Molecules, and Ions. 2 The Power of 10 nceopticsu/powersof10/

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.

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.

Atomic Structure.

Atomic Theory and the Atomic Model. Objectives Describe evidence that Greek philosophers used to develop the idea of atoms. Distinguish between a scientific.

UNIT 2 Atoms, Molecules, and Ions. 1. Each element is composed of extremely small particles called atoms. 2. All atoms of a given element are identical.

Atoms: The Building Blocks of Matter Chapter 3 Pages

Chapter 3 – Atoms: The Building Blocks of Matter

Atoms – The Building Blocks of EVERYTHING

2.1 History of the Atom Objectives S1 and S2

Presentation transcript:

Atoms and Molecules By Doba Jackson, Ph.D.

Outline of Concepts in this chapter Law of Constant Composition (sec. 2-4) –Mass Percentages Dalton’s Atomic Theory (sec. 2-5) –Postulates Atomic and Molecular Mass (sec. 2-7, 2-8) –Atomic Mass Unit (amu) Protons, Neutrons, and Electrons (sec 2-9)

Dalton’s Atomic Theory 1.Elements are made up of tiny particles called atoms. 2.Each element is characterized by the mass of its atoms. 3.Chemical combination of elements to make different chemical compounds called molecules. 4.Chemical reactions only rearrange the way that atoms are combined in molecules; the atoms themselves don’t change.

Law of Constant Composition 2Hg2HgO Chemical Formula O2O2 + Chemical Equation 1)All matter is made of a specific composition of elements from the periodic table. 2)The mass percentage of each element in a pure molecule is conserved.

Law of Constant Composition Chemical Formula 2Hg2HgOO2O2 + Chemical Equation HgO Mass percentage of mercury Mass percentage of oxygen

Suppose we analyze 2.83 g of Lead Sulfide, PbS (consists of lead and sulfur), and find that it consist of 2.45 g of lead (Pb) and.380 g of sulfur (S). Calculate the mass percentages of lead (Pb) and sulfur (S) in the sample. Example % Lead (Pb) % Sulfur (S)

Definitions that lead to Dalton’s Atomic Theory Law of Constant Composition: The relative amount of each element in a particular compound is always the same regardless of the source of the compound, or how the compound was prepared. Law of Multiple Proportions: This law says that when a given element, (X), combines with another element, (Y), then the ratio of masses of X and Y are small whole numbers. Law of Conservation of Mass: For any closed system, the mass of the system will remain constant over time

Law of Multiple Proportions Law of Multiple Proportions: Elements can combine in different ways to form different compounds, with mass ratios that are small whole-number multiples of each other. Compound Grams of oxygen Grams of nitrogen Ratio Nitric Oxide 8.10 grams7.60 grams1.07 : 1.00 NO Nitrous Oxide 16.3 grams8.1 grams2.01 : 1.00 NO 2

Law of Multiple Proportions Law of Multiple Proportions: Elements can combine in different ways to form different compounds, with mass ratios that are small whole-number multiples of each other.

Law of Conservation of Mass: Mass is neither created nor destroyed in chemical reactions. Aqueous solutions of mercury(II) nitrate and potassium iodide will react to form a precipitate of mercury(II) iodide and aqueous potassium iodide.

Law of Conservation of Mass: Mass is neither created nor destroyed in chemical reactions. Hg I 2 (s) + 2KNO 3 (aq)Hg(NO 3 ) 2 (aq) + 2K I(aq) 4.55 g g = 6.57 g 3.25 g g = 6.57 g

Dalton’s Atomic Theory 1.Elements are made up of tiny particles called atoms. 2.Each element is characterized by the mass of its atoms. 3.Chemical combination of elements to make different chemical compounds called molecules. 4.Chemical reactions only rearrange the way that atoms are combined in molecules; the atoms themselves don’t change.

Molecules are groups of atoms joined together

Each element has a unique individual mass (atomic mass) Atomic mass: The mass of a single element Molecular mass: The mass of a single molecule

Atomic masses can be used to find mass percentages Find the mass percentages of lead (Pb) and sulfur (S) in lead sulfide (PbS). Use the periodic table. Molecular mass of PbS Atomic mass of Pb Atomic mass of S = amu amu = amu % Lead (Pb) % Sulfur (S)

What is the atom made of? Cathode-Ray Tubes: J. J. Thomson (1856–1940) proposed that cathode rays must consist of tiny, negatively charged particles which we now call electrons. JJ Thompson reasoned that these cathode rays come from negatively charged particle called electrons.

Subatomic particles of the atom

Atomic Structure: Protons and Neutrons Rutherford’s Scattering Experiment Ernest Rutherford (1871–1937) directed a beam of alpha particles at a thin gold foil. A very small number, (about 1 in every 20,000) were deflected at an angle.

Rutherford’s Scattering Experiment Rutherford proposing that an atom must be almost entirely empty space and have its mass concentrated in a tiny central core that he called the nucleus.

A comparison of subatomic particles The mass of the atom is primarily in the nucleus.

A comparison of subatomic particles The charge on a proton is opposite the charge of the electron

Atomic Numbers, Mass Numbers, Isotopes Atomic Number (Z): Number of protons in an atom’s nucleus. Equivalent to the number of electrons around the atom’s nucleus. Mass Number (A): The sum of the number of protons and neutrons in an atom’s nucleus. This is the atomic mass in units of amu (1 amu = x g). Isotopes: Atoms with identical atomic numbers but different mass numbers.

How to write an atoms atomic numbers, mass numbers for different Isotopes Carbon-14 C 14 6 Atomic number Mass number Carbon-12 C 12 6 Atomic number Mass number 6 protons 6 electrons 8 neutrons 6 protons 6 electrons 6 neutrons

Atomic Mass, Atomic Number The mass of 1 atom of carbon-12 is defined to be 12 amu. Atomic Mass: The weighted average of the isotopic masses of the element’s naturally occurring isotopes.

Why is the atomic mass of the element carbon amu? Carbon-12:98.89 % natural abundance amu Carbon-13:1.11 % natural abundance amu Carbon-14: 1 x % natural abundance amu = amu = (12.00 amu)(0.9889) + ( amu)(0.0111) = amu amu Average mass of a Carbon atom Atomic masses on the periodic table are weighted averages of all naturally occurring isotopes