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.
Cost of steel per ton is about USD 777 and fabrication + erection cost is about USD 266. But this is for industrial applications upto 14 meters height.This may be high for high rise buildings but fabrication and erection costs generally do not cross the supply cost.t that time, fabricated and delivered, pre-bid price per ton was $1200 to $1500 per ton for structural. $1500 to $2500 for miscellaneous steel. Call a local contractor or erector for erection costs.