Beyond the Atom

actinium active deposit amount atomic weight Avogadro's constant Brownian movement canal rays charge carried chemical cloud counting cubic centimetre curves decay deflected detected diameter direct discovery droplets earth effect electric field electron electropositive elements energy equilibrium ether experiment experimental fact fall to half-value fluorescent formula gases Geiger gives glass grains gram of radium half value heat helium hydrogen atom ionic charge ionizing ions J. J. Thomson kathode rays known light liquid magnetic field mass means measured method microns milligram millimetre million minute Mme Curie molecular motion nature negative charge number of molecules observed obtained oxygen penetrating photographic physical plate polonium positive charge pressure properties radio-active radio-active changes radium bromide radium emanation ring Rutherford and Soddy showed solution spectroscope spectrum speed substances temperature theory thorium emanation trace transformed uranium vacuum tube vapour velocity vessel wire X-rays