Farm system boundaries: Discussion of system boundaries in Chapter 3 mainly relates to farms of this type. Briefly, boundaries of Type 2 farm systems (and of Types 1, 3 and 4) segregate them distinctly from the external world, but the boundaries between individual farms are relatively weak.
What is Chromium? Chromium is a steel-gray lustrous metal that is important as an additive in the manufacture of steel alloys (chrome steel, chrome-nickel steel, stainless steel) and greatly increases the durability and resistance of these metals; hence its use in metal prosthetic implants.
Properties of chromium. Chromium is a transition metal in Group 6 on the Periodic Table of Elements. In its pure form, chromium is a steel-gray, lustrous hard metal that has a high polish.It has many compounds that are all colored. [See Periodic Table of the Elements ].Of the compounds, the most important are the chromates of sodium and potassium; the dichromates; and potassium and ammonium chrome alums.hromium is a transition metal in Group 6 on the Periodic Table of Elements. In its pure form, chromium is a steel-gray, lustrous hard metal that has a high polish.