How are precautions that researchers in the antarctic take similar to those that students follow in a lab?

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.)

Find the mass in grams of 1.37x1020 particles of h3po4

Mr. rose asked his student to draw a quadrilateral with four unequal sides. an example of this kind of quadrilateral