Context and question: Federal law and treaties, so long as they are in accordance with the Constitution, preempt conflicting state and territorial laws in the 50 U.S. states and in the territories. However, the scope of federal preemption is limited because the scope of federal power is not universal. In the dual-sovereign system of American federalism (actually tripartite because of the presence of Indian reservations), states are the plenary sovereigns, each with their own constitution, while the federal sovereign possesses only the limited supreme authority enumerated in the Constitution. Indeed, states may grant their citizens broader rights than the federal Constitution as long as they do not infringe on any federal constitutional rights. Thus, most U.S. law (especially the actual "living law" of contract, tort, property, criminal, and family law experienced by the majority of citizens on a day-to-day basis) consists primarily of state law, which can and does vary greatly from one state to the next.
What comes before state and territorial laws in the 50 U.S states?
Answer: Federal law and treaties
Context and question: The so-called "Sack of Palermo" is one of the major visible faces of the problem. The term is used to indicate the speculative building practices that have filled the city with poor buildings. The reduced importance of agriculture in the Sicilian economy has led to a massive migration to the cities, especially Palermo, which swelled in size, leading to rapid expansion towards the north. The regulatory plans for expansion was largely ignored in the boom. New parts of town appeared almost out of nowhere, but without parks, schools, public buildings, proper roads and the other amenities that characterise a modern city.
Why did Palermo substancially grow in size?
Answer: reduced importance of agriculture in the Sicilian economy has led to a massive migration to the cities
Context and question: The X-ray crystal density method is primarily a method for determining the Avogadro constant NA but as the Avogadro constant is related to the Planck constant it also determines a value for h. The principle behind the method is to determine NA as the ratio between the volume of the unit cell of a crystal, measured by X-ray crystallography, and the molar volume of the substance. Crystals of silicon are used, as they are available in high quality and purity by the technology developed for the semiconductor industry. The unit cell volume is calculated from the spacing between two crystal planes referred to as d220. The molar volume Vm(Si) requires a knowledge of the density of the crystal and the atomic weight of the silicon used. The Planck constant is given by
Calculating molar volume requires knowledge of what two factors?
Answer:
the density of the crystal and the atomic weight of the silicon used