Why do experiment need to be repeatable ?

Needthe meter is the standard unit for: 1) height 2) length 3) weight 4) mass

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.)

Name the intersection of plane bpq and plane cpq.