![]() While lamenting one's presence in an 'aluminium box' doesn't have quite the same ring, there are several good reasons to appreciate this choice of material. It's a common refrain of the flying-phobic, but maybe they would find comfort in knowing that the box is actually made of aluminium - more than 66000 kg of it, if they're sitting in a jumbo jet. 'I feel like I'm trapped in a tin box at 39000 feet'. Political stability of top reserve holderĪ percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators. The higher the value, the larger risk there is to supply.Ī percentile rank for the political stability of the top producing country, derived from World Bank governance indicators. The percentage of the world reserves located in the country with the largest reserves. The higher the value, the larger risk there is to supply. The percentage of an element produced in the top producing country. Low = substitution is possible with little or no economic and/or performance impact Medium = substitution is possible but there may be an economic and/or performance impact High = substitution not possible or very difficult. The availability of suitable substitutes for a given commodity. A higher recycling rate may reduce risk to supply. The percentage of a commodity which is recycled. The number of atoms of the element per 1 million atoms of the Earth’s crust. This is calculated by combining the scores for crustal abundance, reserve distribution, production concentration, substitutability, recycling rate and political stability scores. The Chemical Abstracts Service registry number is a unique identifier of a particular chemical, designed to prevent confusion arising from different languages and naming systems.ĭata for this section been provided by the British Geological Survey.Īn integrated supply risk index from 1 (very low risk) to 10 (very high risk). Where more than one isotope exists, the value given is the abundance weighted average.Ītoms of the same element with different numbers of neutrons. This is approximately the sum of the number of protons and neutrons in the nucleus. The mass of an atom relative to that of carbon-12. The transition of a substance directly from the solid to the gas phase without passing through a liquid phase.ĭensity is the mass of a substance that would fill 1 cm 3 at room temperature. The temperature at which the liquid–gas phase change occurs. The temperature at which the solid–liquid phase change occurs. The arrangements of electrons above the last (closed shell) noble gas. These blocks are named for the characteristic spectra they produce: sharp (s), principal (p), diffuse (d), and fundamental (f). The atomic number of each element increases by one, reading from left to right.Įlements are organised into blocks by the orbital type in which the outer electrons are found. Members of a group typically have similar properties and electron configurations in their outer shell.Ī horizontal row in the periodic table. b) Show that the electric potential difference between the two nearest surfaces of the wires is given by: ∣ V ∣ = π ϵ 0 λ ln ( a d − a ) c) State whether the energy per unit charge is higher at the surface of the positively or negatively charged wire.A vertical column in the periodic table. This is shown in Figure 1 below: a) Using Gauss' Law, determine the total electric field at a distance r from the positively charged wire, along the line joining the centres of the two wires. Let one be positively charged with a charge per unit length of + λ, and the other is negatively charged with a charge per unit length of − λ. Each has a circular cross-section of radius a. ![]() Consider two identical infinitely long parallel wires made of an insulating material. Relative atomic mass of copper = 63.6 u Relative atomic mass of aluminium = 27.0 u Proton mass m p = 1.67 × 1 0 − 27 kg Density of silver: ρ = 10, 500 kg m − 3 Density of copper = 8.9 × 1 0 3 kg / m 3 Density of aluminium = 2.7 × 1 0 3 kg / m 3 Charge of an electron e = 1.6 × 1 0 − 19 C Permittivity of free space: ε 0 = 8.85 × 1 0 − 12 Fm − 1 Silver relative atomic mass = 108 amu Charge of an electron: = 1.6 × 1 0 − 19 C 1. ![]()
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