Extensive properties are those which depends on the amount of matter being measured.like mass and volume.
Here density is not an extensive property even it is the ratio of mass and volume which both depend on matter. Since it is ratio so regardless of how much sample is measured it can't change.
Suppose you have a metal block density and you cut out some portion of it, think does compactness of block change? No.it will remain as before. the density will always const.even if you remove some portion.
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