[DOC] [TLE] Atomic Origins: Chapter Problems Big Bang Class Work 1. How old ... [PAR] 10. How did scientists know that the cathode rays were negatively charged? 11. 
What about electrons allow them to be some of the fastest traveling sub atomic 
particles? 12. ... 20. Based off of the first experiments into the composition of 
atoms, why were neutrons ... A carbon nucleus contains 6 protons and 7 neutrons
. [DOC] [TLE] Isotopes of carbon - Wikipedia [PAR] Carbon (C) has 15 known isotopes, from 8C to 22C, of whichC andC are stable. 
... The least stable isotope is 8C, with a half-life of 2.0 x 1021 s. Averaging over 
natural abundances, the relative atomic mass for carbon is ... Carbon-11 or 11C 
is a radioactive isotope of carbon that decays to boron-11. ....  (28.0%), 20. N. [DOC] [TLE] PET Lab [PAR] To understand the function of isotopes in PET scans, let's talk briefly about ... The 
next strongest form of radiation is  (beta) radiation. -radiation turns out to be ... 
This process of atomic degeneration is radioactive decay. ... Its half-life, or the 
time it takes half of the Carbon-11 to decay into Boron-11 is approximately 20 min
. [DOC] [TLE] pamela positron fraction: Topics by WorldWideScience.org [PAR] We extract the positron and electron fluxes in the energy range 10 - 100 GeV by 
... cutoff may potentially fit the rising positron ratio measured by the PAMELA 
satellite. ... If they are indeed unstable, their decay into positrons might occur at a 
...... Among the isotope emissions have carbon isotopes are (11C), of the oxygen
... [DOC] [TLE] acceleration type biological: Topics by WorldWideScience.org [PAR] Carbon and oxygen could not supply the large energy/nucleon that is ... However
, the RBE values for the frequency of micronucleated cells were about 11, ..... with 
accelerated heavy ions carried out by the Biology and Medicine Division of ...... It 
takes about 20 min [2% of the cell doubling time] to irradiate all the 20 samples. [DOC] [TLE] Atomic Awakening - James Mahaffey - Scribd [PAR] The gradual transformation of uranium begins with a decay into the element ..... in 
nuclear physics began ripping atoms to pieces in the 20th century. ...... The half-
life of the only known radium isotope measured at 1,620 years. ...... An example 
of beta-plus decay is a carbon-11 nucleus decaying into a boron-11 nucleus. [DOC] [TLE] cast iron carbon: Topics by Science.gov [PAR] Further, gray cast iron wear was more sensitive to carbon content than was white. 
.... INTERIOR VIEW WITH CASTING MACHINE COOLING A 20' IRON PIPE .... 49 
Transportation 3 2014-10-01 2014-10-01 false Remedial measures: Cast iron 
...... This document is part of Volume 11 'Ternary Alloy Systems: Phase Diagrams,
... [DOC] [TLE] abundant carbon dioxide: Topics by Science.gov [PAR] 1; 2; 3; 4; 5;  ... The isotopic composition of carbon dioxide in the Martian 
atmosphere from the ... Foster, John; And Others ... The seasonal CO2 cycle on 
Mars refers to the exchange of carbon dioxide between ... 2003-11-18 .... 
Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the 
..... 2009-10-20. [DOC] [TLE] 1 [PAR] A precision measurement of the Michel parameter \ in polarised muon decay. 11 
... An optical baffle made from thermally conductive carbon fibre. 41 ... u+SR on 
charge density ordering 5-4-10 intermetallic compounds. 89 ..... value 
superseded the nearly canonical value of 0.805(11) fm ...... layer will be upset 
after 10 min. [DOC] [TLE] ionizing radiation - BVSDE [PAR] Sep 30, 1999 ... An atom consists of one nucleus, made of protons and neutrons, and many ... 
naturally occurring radioactive materials such as carbon-14 and ... neutron 
changes into a proton and throws out a negative beta (pronounced bay' tah) 
particle. .... exposed to radiation from x ray exams (11%), nuclear medicine... [DOC] [TLE] health occupations entrance exams - Central Georgia Technical ... [PAR]

Question: (Jon of the Clue Crew explains the diagrams on the monitor.)  For 5 out of 10 carbon-11 atoms to decay into boron-11, it takes 20 minutes, which is this measure for the carbon-11 isotope
Answer: the half-life