The atoms that make up a molecule can be of the same element or different types. Diatomic molecules are a specific class of molecules that consist of two molecules of the same element. If the molecule is composed of atoms of at least two different elements, it is a chemical compound.
The cost of light rail construction varies widely, largely depending on the amount of tunneling and elevated structures required. A survey of North American light rail projects shows that costs of most LRT systems range from $15 million to over $100 million per mile.he cost of 17 miles (27 km) of highway improvements and 19 miles (31 km) of double-track light rail worked out to $19.3 million per highway lane-mile and $27.6 million per LRT track-mile. The project came in under budget and 22 months ahead of schedule.
Thatâs basically $3.5 million per kilometre of railway in 2001 dollars. Indexed to 2007 dollars, the cost is $4.12 million per kilometre for above ground double track rail, assuming no property acquisition.Stations are not included.trangely, other parts of the report cost the tunnel at $7 billion and DART at $250-300 million â thereâs no consistency. The lowest cost figures give a per km cost of around $347 million for rail tunnel (presumably with stations included) and $42.3 million for above ground rail.