Helium only possesses two valence electrons, while the other noble gasses posses eight
Answer: The mass of the sample is 1264.800 kg.
Explanation:
Mass of the piece of copper = m
Volume of the copper price = 



m = 1,264,800 g = 1,264.800 kg (1 kg = 1000 g)
The mass of the sample is 1264.800 kg.
Answer:
The volume occupied by molecules becomes a significant part of the total volume.
Attractions between molecules cause a reduction in volume.
Explanation:
C is wrong. The masses of molecules are constant.
1.9000 kilogram/cubic meter
8400 kilogram/cubic meter
19300 kilogram/cubic meter