Isotopes Rev. 022609 Pisgah High School M. Jones.

Slides:

Advertisements

Similar presentations

4.3: HOW ATOMS DIFFER ATOMIC NUMBER

Advertisements

Suzanne D'Anna1 Composition of Matter. Suzanne D'Anna2 Composition of Matter l all matter is composed of ELEMENTS l elements cannot be decomposed or broken.

Average Atomic Mass & % Abundance

 An arrangement of elements in which the elements are separated based on properties.

Environmental Science Introduction to Nuclear Energy Lecture Notes

Atomic Symbols and Isotopes

Review of Atomic Model. Key Words subatomic particle energy levels atomic mass protonisotope electronneutronion atomic mass unit (u)atomic number.

 Protons, neutrons, electrons too  Make up the atoms all around you!

Average Atomic Mass Unstable nuclei and Radioactive Decay.

Wake-up 1.Explain the relationship between the following: atomic number, mass number, protons, neutrons, and electrons. 2.How do you find the number of.

Nuclear Chemistry Last revision: M. Jones Pisgah High School.

Atoms – a closer look at elements

How do atoms differ? Section 4.3.

Chapter 4.  Smallest part of an element that retains the properties of that element  all elements are made of indivisible atoms.

Mass Number Atomic Number equals the # of... NUCLEUS ELECTRONS PROTONS NEUTRONS NEGATIVE CHARGE POSITIVE CHARGE NEUTRAL CHARGE ATOM.

Section 2: The Structure of Atoms

Isotopes Atoms of the same element that different mass numbers

Nuclear Chemistry Nine Mile Oswego, NY.  Radioisotope – an isotope that is radioactive  Example: Carbon-14  Radioactive isotopes can be naturally occurring,

Nuclear chemistry.

Alpha, Beta, and Gamma Decay

Chapter 3 Atoms and Elements 3.5 Atomic Number and Mass Number 1.

LecturePLUS Timberlake1 The Atom Atomic Number and Mass Number Isotopes (Take out your Periodic Tables)

SL Chemistry Tuesday September 22nd Agenda Begin Topic 2 - Atomic Structure.

1.3 Understanding Atomic Mass. A Review: Subatomic particles Electron Proton Neutron NameSymbolCharge Relative mass Actual mass (g) e-e- p+p+ nono +1.

The Atom The smallest particle into which an element can be divided and still retain all of the properties of that element.

Number of Protons = Number of Electrons Number of Protons = Atomic Number Atomic Mass = Protons + Neutrons.

Nuclear Chemistry Only one element has unique names for its isotopes … Deuterium and tritium are used in nuclear reactors and fusion research.

Atomic Structure Distinguishing Among Atoms Prentice-Hall Chapter 4.3 Dr. Yager.

Isotopic Abundance Reminder: bring a calculator to class.

What is electromagnetic radiation? radiation moving at the speed of light.

Radiation. Atomic Anatomy Atoms –electrons (e-) –protons (p+) –neutrons (n)

Transmutation- When the nucleus of one element changes to the nucleus of another Stability- Most elements are very stable - Those above atomic number.

Isotopes Average Atomic Mass. Isotopes  Atoms of the same element (same atomic number) with different mass numbers  Atoms with the same number of protons,

NOTES – 4.3: Atomic Number, Mass Number, Isotopes and Atomic Mass.

Section 4.3 How Atoms Differ. Objectives Explain the role of atomic number in determining the identity of an atom Define an isotope and explain why atomic.

Wake-up Explain the relationship between the following: atomic number, mass number, protons, neutrons, and electrons. How do you find the number of electrons.

Chapter 5 Notes.  The atomic mass of an element is a weighted average mass of the atoms found in nature.  If you were to mass an oxygen atom, would.

Atomic Structure.  Atomic number – the number of protons in the nucleus of an atom ( ID of element )  Mass number– sum of protons and neutrons in an.

Section 4.3 How atoms differ. Atomic Number Represents three things in a neutral atom: 1. What element it is 2. The number of protons in each atom 3.

Isotopes. The Nucleus  The number of protons in the nucleus of an atom is unique to each type of element  BUT, the nuclei of the same type of element.

Atomic Structure. I. Atoms The atom is the basic unit of matter.

Atomic Structure What are atoms made of? How are atoms put together? What are Elements? Isotopes?

Chapter 4 Structure of the Atom. Section 4.1 Democritus ( BC) –Matter is composed of empty space through which atoms move –Atoms are solid, homogeneous,

Atomic Mass. Atomic mass Most of the mass of an atom is in the nucleus. Most of the mass of an atom is in the nucleus. The nucleus is where all of the.

Isotopes and Average Atomic Mass Chemistry 11- Chapter 1 Section 4.

Parts of the Atom … from Discovery to Reality. NUCLEUS PROTONS ✚ Positively charged particles Mass = 1 amu NEUTRONS No charge or neutral Mass = 1 amu.

Atomic Structure - Bellwork What experiment did Rutherford perform that identified positively charged nucleii in an atom? What do we call Thomson’s atomic.

 Atomic Theory & Nuclear Changes Sarah Fleck 2015 – 2016 Chemistry.

1 Isotopes & Ions. What’s in an atom of a given element? An atom has three subatomic particles: Proton = positive (+) charge Neutron = no charge Electron.

Atomic Structure and Isotopes. Recap: Atomic Structure An atom is the simplest form of an element that can take part in a chemical reaction Three subatomic.

Chapter 4. Chapter 4 Terms 1.Atom 2.Electron 3.Nucleus 4.Proton 5.Neutron 6.Atomic number 7.Isotope 8.Mass number 9.Atomic mass 10.Radioactivity 11.Alpha.

Essential Question: How do atoms of the same element differ?

1 The Atom Atomic Number and Mass Number Isotopes.

Same Element Different Atom- Isotopes All atoms of a particular element are not exactly alike. Some elements have atoms with different masses (isotopes)

ATOMIC STRUCTURE P + = PROTON N o = NEUTRON E --- = ELECTRON DIFFERENT WAYS TO WRITE ELEMENTS & THEIR SYMBOLS Phosphorus—31 AND P ***NEUTRONS =

Day 8 Chapter 4 Section 4.

SNC1D Isotopes.

Average Atomic Mass In nature, most elements are a mixture of different isotopes The mass of a sample of an element is a weighted average of all the isotopes.

4.2 – NOTES The Mass of the Atom

Average Atomic Mass.

Atomic Structure.

A B 21085At Fe Mo 5827Co 3216S Pb4+ Symbol

ISOTOPES AVERAGE ATOMIC MASS

CHEMISTRY REVIEW For Atomic Structure Test

Nuclear Chemistry.

5.2 - Nuclear Chemistry.

Atoms – a closer look at elements

Element properties & isotopes

Presentation transcript:

Isotopes Rev Pisgah High School M. Jones

Isotopes … …have the same number of protons and electrons but different numbers of neutrons. Therefore, isotopes of the same element have different masses.

Isotopes … Atomic number - the number of protons in the nucleus of an atom Mass number - the number of protons added to the number of neutrons …have different mass numbers but the same atomic number.

Symbols for Isotopes E A Z Symbol of Element Mass number Atomic number A is the symbol for mass number Z is the symbol for atomic number

Symbols for Isotopes U Symbol of Element Mass number Atomic number

Symbols for Isotopes U Mass number Symbol of Element Atomic number

Symbols for Isotopes U -235 Symbol of Element Mass number How do you know the atomic number? Find U in the periodic table. Z = 92

Determining the Atomic Number and Mass Number The atomic number is the number of protons. The atomic number is the number of protons. The mass number is the sum of the protons + neutrons. The mass number is the sum of the protons + neutrons. Consider an atom of aluminum with 13 protons and 15 neutrons. What is Z and A?

Determining the Atomic Number and Mass Number A = #p + + #n = 28 Answer: Atomic number: Z = 13 Mass number: A = 28

Finding the number of Protons, Neutrons, and Electrons The atomic number is the number of protons in the nucleus. The number of electrons in a neutral atom equals the number of protons.

Finding the number of Protons, Neutrons, and Electrons # of neutrons = A - Z The number of neutrons is the difference between the mass number and the atomic number.

Finding the number of Protons, Neutrons, and Electrons Look at the Periodic Table and find the element by using the symbol U-235 A = 235 protons + neutrons = 235 Z = 92 protons = 92 electrons = 92

Finding the number of Protons, Neutrons, and Electrons U-235 Z = 92 protons = 92 electrons = 92 A = 235 protons + neutrons = prot.& neut protons 143 neutrons

Finding the number of Protons, Neutrons, and Electrons Q. Find the number of neutrons in the Ba-137 isotope. A. In the Ba-137 isotope … … Z = 56 and A = – 56 = 81 neutrons

Finding the number of Protons, Neutrons, and Electrons Fill in the following table.

Finding the number of Protons, Neutrons, and Electrons ElementSymbolZA#p#n#e Zinc66 In Rn

ElementSymbolZA#p#n#e ZincZn In Rn

ElementSymbolZA#p#n#e ZincZn IndiumIn Rn

ElementSymbolZA#p#n#e ZincZn IndiumIn StrontiumSr Rn

ElementSymbolZA#p#n#e ZincZn IndiumIn StrontiumSr LeadPb Rn

ElementSymbolZA#p#n#e ZincZn IndiumIn StrontiumSr LeadPb RadonRn

ElementSymbolZA#p#n#e ZincZn IndiumIn StrontiumSr LeadPb RadonRn BromineBr

How are isotopes of the same element alike and different? Alike: 1. Number of protons and electrons 2. Atomic number 3. Chemical properties Different: 1. Number of neutrons 2. Mass Number 3. Atomic weight of the isotopes

Which of the following is the same for the three isotopes of magnesium? 1.The atomic number of 12 2.The number of protons and electrons 3.The number of neutrons 4.The atomic weight of AMU 5.The reaction with hydrochloric acid 6.The speed of gaseous Mg atoms

Which of the following is the same for the three isotopes of magnesium? 1.The atomic number of 12 All three isotopes of magnesium have the same atomic number. Same

Which of the following is the same for the three isotopes of magnesium? 2. The number of protons and electrons All isotopes of the same element have the same number of protons in the nucleus, and electrons outside the nucleus. Same

Which of the following is the same for the three isotopes of magnesium? 3. The number of neutrons The number of neutrons varies with the isotope. Different isotopes have different numbers of neutrons. Not the same

Which of the following is the same for the three isotopes of magnesium? 4. Atomic weight of AMU Mg-24  AMU Mg-25  AMU Mg-26  AMU Not the same

Which of the following is the same for the three isotopes of magnesium? 5. The reaction with HCl All isotopes of the same element react the same chemically. Same The number and arrangement of electrons is the same for each isotope.

Which of the following is the same for the three isotopes of magnesium? 6. The speed of gaseous Mg atoms The speeds of atoms depend on mass. Heavier atoms move more slowly, and lighter atoms move faster. Not the same

How did knowing that the speeds of gaseous isotopes are different, allow the United States to win World War II?

Who were the two guys responsible for winning World War II? Fat Man, and … Little Boy Atomic bombs dropped on Hiroshima and Nagasaki

Manhattan Project Oak Ridge, TN Gaseous Diffusion To sustain a nuclear chain reaction, uranium must be at least 4% U-235. Most naturally occurring uranium is U-238 Less than 1% of naturally occurring uranium is U-235

To make either bomb-grade uranium, or fuel for a nuclear reactor you need enriched uranium. Enriched uranium has a higher percentage of U % for a reactor, 90% for a bomb.

The gaseous diffusion plant at Oak Ridge was used to make enriched uranium. The uranium oxide is reacted with fluorine to make UF 6 which is a gas. The UF 6 is introduced into a container with a porous barrier.

The molecules of UF 6 containing U- 235 diffuse through the porous barrier slightly faster. Produces a slightly higher percentage of U-235 in the UF 6. Produces a slightly higher percentage of U-235 in the UF 6. Then the process is repeated many times.

The K-25 building at Oak Ridge

Atomic Weights

Calculating Average Atomic Weight Atomic mass (atomic weight) is the weighted average of the masses of all the isotopes of the element.

Calculating Average Atomic Weight A weighted average puts more weight or importance on one value that another. Example: Compute the average age of everyone in this room.

Calculating Average Atomic Weight Suppose there were two isotopes of the element Q. Q-30 95% Q-32 5% Determine the average atomic mass.

Calculating Average Atomic Weight Is the average atomic weight 31? ( ) / 2 = 31 Assume 100 atoms of Q: 95 x 30 amu = x 32 amu = x 32 amu = 160 / 100 = 30.1 amu 3010 Much closer to 30

Calculating Average Atomic Weight of each naturally occurring isotope. of each naturally occurring isotope. You can compute the atomic weight by knowing … … the mass (M) and … the relative abundance (RA)

Calculating Average Atomic Weight The mass is the actual mass of the isotope in amu. The relative abundance is the percentage of that isotope divided by 100.

Calculating Average Atomic Weight Example: Suppose that 48.6% of the atoms of zinc in the world were Zn-64. Then the relative abundance of zinc-64 would be

Calculating Average Atomic Weight (M 3 * RA 3 ) … (M 2 * RA 2 ) + (M 1 * RA 1 ) + Average atomic weight = Mass of each isotope times its relative abundance

Calculating Average Atomic Weight Calculate the average atomic weight for Cu-63 and Cu-65. Actual mass of isotope in AMU Percent abundance Cu % Cu %

Calculating Average Atomic Weight AW = AMU AW = ( *.6909) + AW = (M 1 * RA 1 ) + (M 2 *RA 2 ) Calculate the average atomic weight for Cu-63 and Cu-65. ( *.3091)

Calculate the Average Atomic Weight of Chlorine Actual mass of isotope in AMU Percent abundance Cl % Cl % Stop Do the calculations, then continue.

Calculate the Average Atomic Weight of Chlorine Actual mass of isotope in AMU Percent abundance Cl % Cl % AW = ( * ) + ( * ) AW = AMU

Which isotope of Boron is more abundant? B-10 ??? % amu B-11 ??? % amu Give a qualitative answer. A qualitative answer does not require calculations, just thought.

Which isotope of Boron is more abundant? B-10 ??? % amu B-11 ??? % amu B-11 is more abundant because is closer to 10.81, the actual average mass of Boron.

Which isotope of Boron is more abundant? B-10 ??? % amu B-11 ??? % amu Now stop and compute the actual percentages.

Which isotope of Boron is more abundant? B-10 ??? % amu B-11 ??? % amu Did you get 20.00% B-10 and 80.00% B-11?

Some isotope trivia…

Only one element has unique names for its isotopes … Deuterium and tritium are used in nuclear reactors and fusion research.

Some isotopes are radioactive Radioactive isotopes are called radioisotopes. Radioactive isotopes are called radioisotopes. Radioisotopes can emit alpha, beta or gamma radiation as they decay. Radioisotopes can emit alpha, beta or gamma radiation as they decay. Radioisotopes are important in a number of research fields. Radioisotopes are important in a number of research fields.

Man-made Isotopes Man made isotopes are made by bombarding atoms with streams of protons or neutrons. Man made isotopes are made by bombarding atoms with streams of protons or neutrons. Cobalt-59 occurs naturally. Cobalt-60 occurs in reactors after neutron exposure. Cobalt-59 occurs naturally. Cobalt-60 occurs in reactors after neutron exposure.

Uses for Isotopes Various radioisotopes are used to kill cancer cells. (Co-60, Bi-212) Various radioisotopes are used to kill cancer cells. (Co-60, Bi-212) Radioisotopes are used in imaging living and nonliving systems. Tc-99 Radioisotopes are used in imaging living and nonliving systems. Tc-99 Radioisotopes are used as tracers in chemical reactions. Radioisotopes are used as tracers in chemical reactions.

Isotopes