Units are necessary to evaluate quantities. Obviously, a rhinoceros is heavier than a dog, but to know by how much, we need some reference units. Moreover, rhinoceroses don’t all have the same weight. We are thus in need of a consistent unit to measure the weight of objects. The same problem appears for all the […]
Posts from January 2018
Chapter 1: Elementary physics – Introduction
Definitions and laws “One of the noblest desire of the man is to know the laws ruling the Universe, and those who contributed to enlighten some of the mysteries were always admired by their peers; they appear as privileged, wearing on them the divine light, a through centuries the generations gaze upon their indelible work […]
Chapter 10c: The Aluminium-Nickel group
Addition of NH4Cl, NH4OH and (NH4)2S to a solution containing all the cations not precipitated in the preceding groups results in the precipitation of aluminium, chromium and iron(II) as hydroxides, and manganese, nickel, cobalt, iron(II) and zinc as sulphides. Note that we used NH4OH and (NH4)2S in several tests of the preceding groups to separate […]