A neutron needs protons around to keep this from happening.A cell can survive an otherwise lethal dose of radiation ifthe dose is spread over a long period of time to allow intervals for healing.Born in 1867 as Marie Sklodowska in Warsaw, then part of the Russian Empire, she received her general education in localschools with some scientific training from her father, asecondary-school teacher.
Sometimes a radiated cell will survivewith a damaged DNA molecule.
Roentgendiscovered these “new kind of rays” produced by a beam of “cathode rays” (laterfound to be electrons) striking the glass surface of a gas-discharge tube.
Tinyflashes of light, or scintillations, are converted into electric signals by specialphotomultiplier tubes. γβαLead Aluminum Radioactivesource Paper F I G U R E 3 3 .
Theamount of radioactive fertilizer taken up by the plants can be easily measured withradiation detectors.
6The successions of radioactive decays of to , an isotope of lead, isshown in Figure 33.
The combined beam comes froma radioactive source placed at thebottom of a hole drilled in a leadblock.Gamma photons provideinformation about nuclear structure, much as visible and X-ray photons pro-vide information about atomic electron structure.He foundthat X-rays could pass through solid materials, could ionize the air, showed norefraction in glass, and were undeflected by magnetic fields.C H A PTE R 3 3 TH E ATOM I C N U C L E U S A N D RA D I OAC TIVIT Y 583Cells are able to repair most kinds of molecular damage caused by radiation if theradiation is not too severe.)C H A PTE R 3 3 TH E ATOM I C N U C L E U S A N D RA D I OAC TIVIT Y 589maintained at a high voltage (about 10 k V).Whenradiation is sufficient to kill cells, the dead cells can be replaced by new ones (exceptfor most nerve cells, which are irreplaceable).