initial hardness
31Calcium chloride — Calcium chloride …
32Marine aquarium — See also: Reef aquarium A marine aquarium …
33technology, history of — Introduction the development over time of systematic techniques for making and doing things. The term technology, a combination of the Greek technē, “art, craft,” with logos, “word, speech,” meant in Greece a discourse on the arts, both… …
34Chromium — This article is about the chemical element. For other uses, see Chromium (disambiguation). vanadium ← chromium → manganese ↑ Cr ↓ Mo …
35Molybdenum — niobium ← molybdenum → technetium Cr ↑ Mo ↓ W …
36Chobham armour — A pre series American M1 Abrams, the first main battle tank type to be protected by Chobham armour …
37Carbon steel — Iron alloy phases Ferrite (α iron, δ iron) Austenite (γ iron) Pearlite (88% ferrite, 12% cementite) …
38geology — /jee ol euh jee/, n., pl. geologies. 1. the science that deals with the dynamics and physical history of the earth, the rocks of which it is composed, and the physical, chemical, and biological changes that the earth has undergone or is… …
39platinum group — ▪ chemical element group Introduction six metals, in order of increasing atomic weight, ruthenium (Ru), rhodium (Rh), palladium (Pd), osmium (Os), iridium (Ir), and …
40Lime softening — Lime softening, also known as Clark s process[1], is a type of water treatment used for water softening. In the USA, it is used primarily in the Midwest, Florida and Texas. It utilizes the addition of lime (calcium hydroxide) to remove hardness… …
