Physical is texture. chemical is ability to react with other elements. chemical is ability to conduct heat. hardness is physical. lack of ability to rust is chemical. state is physical.
When ammonium carbonate is heated it decomposes to give ammonia gas, carbon dioxide gas and water. The equation for the decomposition is;
(NH4)2CO3(s) = 2 NH3 (g) + CO2(g) + H2O(l)
A glowing splint would extinguish almost immediately because of the presence of carbon dioxide. Carbon dioxide does not support burning which is the property that makes it used a s a fighter extinguisher.
First row: HCl, ZnCl2, FeCl3, AlCl3, BaCl2, PbCl4
Second row: H3P, Zn3P2, FeP, AlP, Ba3P2, Pb3P4
Third row: HNO3, Zn(NO3)2, Fe(NO3)3, Al(NO3)3, Ba(NO3)2, Pb(NO3)4
Fourth row: ZnO, Fe2O3, Al2O3, BaO, PbO2
Fifth row: HCaF2, Zn(CaF2)2, Fe(CaF2)3, Al(CaF2)3, Ba(CaF2)2, Pb(CaF2)4
Sixth row: H2SO4, ZnSO4, Fe2(SO4)3, Al2(SO4)3, BaSO4, Pb(SO4)2
Well, for one thing, they ensure that a scientist can't claim a certain result, which might be biased and thus inaccurate, because he or she is being paid by, say, big business interests. For another, they ensure that medicines or treatments can't be made available to the public without thorough testing, replication, and peer review.
