Positive electron Equations for Nuclear Reactions Radioisotope Radioactive

Positive electron equations for nuclear reactions

This preview shows page 2 - 4 out of 5 pages.

Positive electron Equations for Nuclear Reactions Radioisotope: Radioactive isotope Number of nucleons will remain the same. The total number of nucleons in reactants is the same as the total number of nucleons in the products Nuclide: a specific isotope Stable nuclides vs. unstable nuclides Emission of Alpha Particles Alpha Particle Same as nucleus of 4He atom 2 protons + 2 neutrons Emitted from the nucleus Plus 2 charge (no electrons) Note that TOTAL number of nucleons is constant Beta Particle Emission Note that a neutron is converted into a proton (number of nucleons constant) and a β particle Example of Positron Emission Number of protons decreases by 1 Number if neutrons increases by 1 Mass number stays the same Atomic number increases by 1 Gamma Ray Emission Generally occurs with α or β emission Not a particle, light wave Energy Think of as a “bookkeeping” event Can greatly affect living cells Not always written into nuclear equation Summary α particle: helium nucleus +2 charge 4 amu β Particle: electron -1 charge
Image of page 2
neutron into a proton + β γ Ray: no mass, only energy usually accompanies another process Positron: e+ +1 charge Proton changes to neutron + β+ Half-Life Definition: The time it takes for half of a radioactive sample to undergo decay Each nuclide has its own half-life, however it is NOT possible to predict it in advance. (It must be determined experimentally.) It does NOT take 2 half-lives for a sample to decay completely. Half-Lives There are more than 2 half-lives involved in radioactive decay of a sample. Each half-life uses up half the REMAINING sample Note that the amount of reactant decreases, and the amount of product increases One cannot predict what the half-life of a radioactive isotope is. Experiments were done to determine halflives. MUST WRITE LIKE THIS- 1.00g 131 53 I 8 days .500g 131 53 I 8 days .250g 131 53 I 8 days .125g 131 53 I .500g 131 54 Xe .750g 131 54 Xe .875g 131 54 Xe 1 half life 8 total 2 half life 16 total 3 half life 24 total NEED TO DETERMINE HALF LIFE FROM A GRAPH FOR TEST
Image of page 3
Image of page 4

You've reached the end of your free preview.

Want to read all 5 pages?

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes