what is the number of atoms present in 6dm^3 of propane gas（C3H6）at room temperature and 1 atmosphere.

Compare and contrast physical changes with chemical changes.

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?

How can a give a full method for the experiment of separating sand from water by filtration? 1-materials 2-steps 3-conclusion also for water and salt separated by the evaporation or distillation process