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Isotopes halflife

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Isotopes halflife

  1. 1. Chemistry: Isotopes<br />
  2. 2. Review on atoms from yesterday:<br />Each element is made of atoms<br />E.g. Oxygen is made of oxygen atoms, gold is made of gold atoms<br />Atoms have a specific atomic number and atomic mass<br />Atomic # = # protons<br /># protons = # electrons<br />Atomic mass – Atomic # = # neutrons<br />(USUALLY!)<br />
  3. 3. ISOTOPES<br />Isotopes are atoms of the same element with a different number of neutrons<br />Most atoms of carbon have 6 protons and 6 neutrons<br />BUT some atoms of carbon have 7 neutrons or 8 neutrons<br />These other kind of carbon atoms are called isotopes. <br />
  4. 4. These isotopes of carbon are called: (pg. 47)<br />Carbon-12<br />Carbon-13<br />Carbon-14<br />These atoms are unstable because the number of protons does not equal the number of neutrons<br />The protons start to repel and release particles to become stable, called radioactive decay<br />
  5. 5. Half - Life<br />We can measure decay by studying half-life<br />Half-life = time for half of the atoms in an element to decay<br />For example, if you start with 10g of carbon-14, after 2 weeks you may have only 5g left. <br />Carbon-14 may be used to examine the age of fossils!<br />
  6. 6. M&Mium activity<br />Each M&M represents one atom of the mysterious element M&Mium. <br />Count the number of M&Miums you are starting with. Record this number on a piece of paper.<br />Shake the M&Miums in your cup and dump them out CAREFULLY onto a clean sheet of paper. Don’t lose any of them!<br />Any M&Miums that have the “M” facing up are radioactive!<br />5) The ones that are blank have decayed to Blankium.<br />6) Remove the Blankium M&Ms and count the remaining M&Miums.<br />7) Shake again, and repeat removing the Blankiums until there are no more M&Miums left! Make sure to record the number of times you shake, too!<br />8) GRAPH the data! Y-axis = Number of M&MiumsX-axis = Number of shakes (number of half-lives)<br />
  7. 7. 5) The ones that are blank have decayed to Blankium.<br />6) Remove the Blankium M&Ms and count the remaining M&Miums.<br />7) Shake again, and repeat removing the Blankiums until there are no more M&Miums left! Make sure to record the number of times you shake, too!<br />8) GRAPH the data! Y-axis = Number of M&MiumsX-axis = Number of shakes (number of half-lives)<br />

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