The stability of triaxial superdeformed shape in odd-odd 160-168 Lu isotopes Tu Ya.
ISOTOPES AND NUCLEAR REACTIONS ISLAND OF STABILITY.
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Transcript of ISOTOPES AND NUCLEAR REACTIONS ISLAND OF STABILITY.
ISOTOPES AND
NUCLEAR REACTIONS
ISLAND OF STABILITY
ISOTOPES
• A VARIATION OF AN ELEMENT, THAT DIFFERS BY THE NUMBER OF NEUTRONS.
• PROTONS CANNOT CHANGE – A PROTON IS LIKE AN ATOMS DNA, ITS WHAT MAKES IT AN ATOM OF A SPECIFIC ELEMENT
• ELECTRONS ARE SO SMALL – THEIR MASS IS NEGLIGIBLE TO THE MASS OF AN ATOM
• NEUTRONS ARE THE ONLY THING THAT CAN CHANGE – CHANGE THE MASS OF THE ATOM
• WHEN AN ATOM VARIES IN THE NUMBER OF NEUTRONS, ITS MASS ALSO VARIES – THESE ARE CALLED ISOTOPES
ISOTOPIC NOTATION
• HOW DO WE DIFFERENTIATE BETWEEN DIFFERENT ISOTOPES?
• ISOTOPES CAN BE WRITTEN IN A LONG FORMAT THAT USES THE ELEMENTS NAME AND MASS
• CARBON – 12
• CARBON – 13
• CARBON - 14
• ISOTOPES CAN BE WRITTEN WITH SYMBOLS JUST LIKE ELEMENTS CAN:
PRACTICE WITH ISOTOPIC NOTATION
Element Isotopic Symbol
Mass Number
Atomic Number
Number of Protons
Number of Electrons
Number of Neutrons
Carbon – 14 14 6 6 6 14-6= 8
Polonium – 210
210 84 84 84 210-84= 126
Aluminum - 27
27 13 13 13 27-13= 14
ATOMIC MASS
• RECALL WHAT ATOMIC MASS IS:
• AVERAGE ATOMIC MASS IS THE MASS OF ALL THE ISOTOPES OF AN ELEMENT COMBINED
• IT IS THE MASS GIVEN ON THE PERIODIC TABLE
• IT IS CALCULATED BY TAKING THE MASS OF EACH ISOTOPE OF AN ELEMENT AND MULTIPLYING EACH ISOTOPES MASS BY ITS ABUNDANCE THEN ADDING ALL THE ISOTOPES TOGETHER.
• (% OF MASS 1)(MASS 1) + (% OF MASS 2)(MASS 2) + (% OF MASS 3)(MASS 3)….. • YOU WOULD DO THIS FOR EACH ISOTOPE OF THE ELEMENT – SOME ELEMENTS HAVE MANY
ISOTOPES
• POLONIUM HAS 25 ISOTOPES AND ALL ARE RADIOACTIVE
AVERAGE ATOMIC MASS PROBLEMS:
• COPPER HAS TWO ISOTOPES: 69.2% OF ALL COPPER HAS A MASS OF 63 AMU, WHILE 30.8% OF ALL COPPER HAS A MASS OF 65 AMU. WHAT IS COPPER’S AVERAGE ATOMIC MASS?
NUCLEAR CHEMISTRY
• RADIOACTIVITY – THE PROCESSES BY WHICH UNSTABLE NUCLEI ACHIEVE STABILITY BY RELEASING RADIATION
• RADIATION – THE PENETRATING RAYS AND PARTICLES EMITTED BY A RADIOACTIVE SOURCE
• RADIOACTIVE DECAY – THE PROCESS IN WHICH UNSTABLE NUCLEI DISINTEGRATES
• RADIOISOTOPES – AN ISOTOPE THAT HAS AN UNSTABLE NUCLEUS AND UNDERGOES RADIOACTIVE DECAY
NUCLEAR REACTIONS
•A REACTION THAT RESULTS IN A DIFFERENT NUCLEUS
• ALL REACTIONS KNOWN UP TO THIS POINT, HAVE NOT CHANGED THE NUCLEUS
• LAW OF CONSERVATION OF MASS
• NUCLEAR REACTIONS DO NOT SEEM TO FOLLOW THIS LAW.
FISSION AND FUSION REACTIONS
FISSION
• NUCLEAR DECAY THAT RESULTS FROM THE NUCLEUS OF AN ATOM SPLITTING IN TO SMALLER PIECES
• HEAVIER ATOM BECOMES A LIGHTER ATOM
• THE IS NUCLEAR ENERGY ON EARTH
• REQUIRES LITTLE TO NO ENERGY (USUALLY)
• RESULTS IN: FREE FLOATING NEUTRONS AND PHOTONS (ENERGY)
FUSION
• NUCLEAR REACTION THAT RESULTS FROM TWO NUCLEI JOINING TOGETHER TO FORM ONE LARGER NUCLEUS
• DOES NOT OCCUR ON EARTH
• IF IT DID, IT WOULD SOLVE OUR ENERGY CRISIS
• RELEASES GAMMA RADIATION FOR EVERY REACTION
• THIS IS WHAT WE COULD USE FOR ENERGY
• REQUIRES TOO MUCH ENERGY TO START THE REACTION
• POWERS ACTIVE STARS
RADIATION
•RAYS AND PARTICLES EMITTED BY THE RADIOACTIVE MATERIAL
• 3 TYPES• ALPHA
• BETA
• GAMMA
ALPHA RADIATION
• ALPHA PARTICLES ARE MADE OF 2 PROTONS AND 2 NEUTRONS
• HAS A +2 CHARGE
• THE ATOMIC MASS DECREASES BY 4 AND THE ATOMIC # BY 2
• IT IS A VERY WEAK TYPE OF RADIATION
• CAN BE STOPPED BY PAPER OR CLOTHING
• LIMITED TO VERY LARGE NUCLEI
• EX: HEAVY METALS
BETA RADIATION• CHANGES A NEUTRON TO A PROTON, EMITS FAST MOVING ELECTRONS FROM
THE NUCLEUS
• -1 CHARGE
• DOES NOT AFFECT MASS BUT INCREASES THE ATOMIC NUMBER BY 1
• CAN BE STOPPED BY: ALUMINUM FOIL, THIN PIECES OF WOOD
GAMMA RADIATION
• HIGH ENERGY RADIATION WAVE OF ELECTROMAGNETIC RADIATION GIVEN OFF BY A RADIOISOTOPE
• NOT A PARTICLE, BUT A WAVE OF ENERGY
• NO CHARGE
• RELEASED WITH ALPHA AND BETA RADIATION
• DOES NOT CHANGE THE MASS OR ATOMIC NUMBER
• VERY HARD TO STOP
• CAN ONLY BE STOPPED BY THICK CONCRETE OR LEAD
HOMEWORK
• PAGE 7 AND 8 IN YOUR PACKETS
• WE WILL COMPLETE PAGE 9 TOGETHER ON THURSDAY – YOU MAY TRY IT IF YOU WANT