Consider the following substances: C, O, H,,H, O, NaCl, CO,, Fe and Fe, Og. Indicate whether each substance is a) an element or a compound, or b) an atom or a molecule.
Element
Compound
Atom
Molecule

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.