Compared to a 26-gram sample of NaCl(s) at STP, a 52-gram sample of NaCl(s) at STP has(1) a different density(2) a different gram-formula mass(3) the same chemical properties(4) the same volume
The answer is (3) the same chemical properties. The two samples are under same condition so they have same density. The gram-formula mass is the property of the matter itself. So it will not change. The volume will change when mass changes.