Na has a high electrical conductivity. Na, when dropped into water, causes the evolution of H 2 gas. Na reacts violently with oxygen. Apple juice is a homogeneous mixture. A snow cone is a heterogeneous mixture.
Steel is a compound.
The basic unit of mass in the SI system is the gram. The basic unit of length in the SI system is the meter. The basic unit of time in the SI system is the second. The basic unit of volume in the SI system is the cubic meter. The basic unit for amount of substance in the SI system is the mole.