2. Al reaccionar el sodio con el cloro para formar cloruro de sodio lo hacen siempre con la misma proporción de masas:
a) Teoría de Dalton
b) Modelo de J. J. Thomson
c) Modelo de Rutherford
d) Modelo de Bohr

Which of the following is an example of how telecommunication devices people do their jobs? a.) a security guard checks the time using a digital watch. b.) a banker does some quick math using a solar calculator. c.) a nurse uses a digital thermometer to take a patient’s temperature. d.) a construction worker reports in to his office using a cell phone.