CHEM 105N 1st Edition Lecture 15Outline of Last Lecture I. Radioactive DecayII. Radioactive IsotopesIII. Types of RadiationIV. Biological Effects of RadiationV. Nuclear ReactionsVI. Alpha DecayVII. Beta DecayOutline of Current Lecture I. Positron EmissionII. Gamma RadiationIII. Radioactive IsotopesIV. Radiation MeasurementsV. Half LifeVI. Decay CurveVII. Calculating Half LivesVIII. Nuclear FissionIX. Nuclear FusionCurrent LectureI. Positron Emission:- A proton is converted to a neutron and positron- New NucleusThe mass number is the sameThe atomic number decreases by one- Positron Emission Tomography:- Uses positron emitters with short half-lives, such as (carbon-11), (oxygen-15), (nitrogen-13), and (fluorine-18)- Uses the positron emitter (fluorine-18) to study: brain function, metabolism and blood flowII. Gamma Radiation:- Energy is emitted by an unstable nucleus in this process Indicated by “m” next to final mass number- Mass number and atomic number of new nucleus are for the same elementIII. Radioactive Isotopes:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Produced when a stable nucleus is converted to a radioactive nucleus by bombarding it with a small particle- Process is called “transmutation”- When nonradioactive B-10 is bombarded by an alpha particle, the products are radioactive N-13 and a neutron- A Geiger counter:- Detects beta and gamma radiation- Uses ions produced by radiation to create an electrical currentIV. Radiation Measurements:- Units of radiation:- Curie (Ci) measures activity as the number of atoms that decay in one second for one gram of radium- Rad (radiation absorbed dose) measures the radiation absorbed by the tissues of the body- Rem (radiation equivalent) measures the biological damage caused by different types of radiation- Becquerel (Bq), which is 1 disintegration per second and the SI unit for radioactivity- Gray (Gy), which is defined as the joules of energy absorbed by 1 kilogram of body tissue and is equal to 100 rad- Sievert (Sv), which is the SI unit for rem, and is equal to 100 rem- A Geiger counter:- Detects beta and gamma radiation- Uses ions produced by radiation to create an electrical currentV. Half Life:- The time for the radiation level to decrease (decay) to one-half of the originalvalueVI. Decay Curve:- Shows decay of radioactive atoms and the remaining radioactive sampleVII. Calculating Half Lives:- 1 half life of 40mg = 20mg- 2 half lives of 40mg= 10mg(continually cut initial in half)Ex. The half life of I-123 is 13 hours. How much of a 64-mg sample of I-123 remains active after 26 hours?1. Calculate the number of half lives by dividing the time (26 hours) by the half life time of I-123=22. Divide 64mg in half twice64/2 =3232/2 =16FINAL ANSWER: 16g remainingVIII. Nuclear Fission:- Nucleus splits into smaller nuclei and several neutrons- Releases energyIX. Nuclear Fusion:- Combines smaller nuclei into larger nuclei- Releases