Which concept in dalton's atomic theory has been modified

An atom's configuration based on its number of electrons ends at 3p4. another atom has seven more electrons. starting at 3p, what is the remaining configuration? 3p63d34s2 3p43d54s2 3p64s23d3 3p44s23d

What volume does 1.70 ×10–3 mol of chlorine gas occupy if its temperature is 20.2 °c and its pressure is 795 mm hg?

If you are told to get 100 ml of stock solution to use to prepare smaller size sample for an experiment, which piece of glassware would you use?