The isotope of lead contains 127 neutrons. Determine the mass number and the number of protons of the isotope

Frictional forces acting on an object are often converted into energy, which causes the temperature of the object to rise slightly.

In the cathode ray tube experiment, j. j. thomson passed an electric current through different gases inside a cathode ray tube in the presence of an electric field. in which two ways did this experiment change scientists’ understanding of the atom?

Select all of the statements which are true. electrons are located in shells or orbits around the atom. electrons orbit slowly around the atom. electrons travel in one flat path around the nucleus of an atom. the valence of an atom is determined by the number of electrons in the atom's outermost shell.