Amineral is scratched by apatite but not by calcite what could it’s hardness value be

Silver tarnishes as silver metal reacts with hydrogen sulfide, h2s, in the air. in this reaction, dark silver sulfide, au2s, covers the surface of silver. when silver is polished, this coating of silver sulfide can be removed from the surface. this makes the silver shiny again. enter the coefficients that balance the tarnishing reaction equation. (type 1 for no coefficient.)

What is the polyatamic ion of thiosulfate

Identify the lewis acid in this balanced equation: ag+ + 2nh3 -> ag(nh3)2+a. ag+b. nh3c. ag(nh3)2+