Asample consisting of 0.10 mol of perfect gas molecules is held by a piston inside a cylinder such that the volume is 1.25dm, the external pressure is constant at 1.00bar and the temperature is maintained at 300 kby a thermostat. the piston is released so that the gas can expand. calculate (a) the volume of the gas when the expansion is complete; (b) the work done when the gas expands; (c) the heat absorbed by the system. hence calculate as tor'

Henry moseley used x-ray experiments to determine the atomic number of elements. how did his discovery contribute to the development of the periodic table? a.it confirmed that elements should be arranged in strict order of increasing atomic mass. b.it led to elements with similar atomic numbers being grouped together. c.it allowed the elements to be placed in strict order of increasing atomic number. d.it showed that the way mendeleev grouped elements together was completely wrong.