True or false the boundaries between the five areas of chemistry are not firm

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

What is conserved in the reaction shown below? h2(g) + cl2 (g) --> 2hcl(g)a. mass onlyb. mass and moles onlyc. mass, moles, and molecules onlyd. mass, moles, molecules, and volume

Which of the following is a physical property flammability heat of combustion solubility and toxicity