Iron comes from Iron Ore via the Forge. Iron Ore can be found in Iron Nodes in the Stalactite layer and Lava layer. The ore has to be harvested with an Extractor, as the node itself cannot be pulled with Power Cells, it also cannot be placed. All Ores can be smelted into bars in a Forge for further processing.
It depends on the substance (water for example has 1000 grams to a liter, other substances have more grams or less grams to a liter depending on a property (called the density measured in grams / liter) of the substance.
Three methods to convert cubic meters to liters are demonstrated in this worked example problem. Three methods to convert cubic meters to liters are demonstrated in this worked example problem. Converting Cubic Meters to Liters - m3 to L Example Problem Meters Cubed To Liters Worked Volume Unit Example Problem