Windows has a Sound window that allows you to manage your computer's audio settings and devices. If you cannot hear sound when it should be playing, head to the Sound window and tell Windows to select the audio input device you are using. 1. Click the Start button and type mmsys.cpl..
The atomic number of lead is 82. That tells us that electrically neutral lead has 82 protons and 82 electrons. The three stable isotopes of lead are 206 Pb, 207 Pb, and 208â¦ Pb. These isotopes have 124, 125, and 126 neutrons per each atom, respectively.
Lead 204, which is not produced by radioactive decay provides a measure of what was original lead. It is observed that for most minerals, the proportions of the lead isotopes is very nearly constant, so the lead-204 can be used to project the original quantities of lead-206 and lead-207.