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. Increasing the number of scans to 256, a total experiment time of 8.8 minutes, shows a very clean spectrum with excellent sensitivity and low noise.A vertical column in the periodic table. A 30 second, 16 scan acquisition is shown below revealing a quintuplet multiplet resulting from the 4 attached Fluorine atoms. We measured a second sample of 1.2M Sodium tetrafluoroborate in D 2O. In this image we expand both the noise and the signal in separate insets to enable you to see the remarkable sensitivity achievable with the Spinsolve benchtop NMR spectrometer. The first spectrum shows the excellent sensitivity of Spinsolve using just 8 scans to acquire a spectrum in only 16 seconds.īy increasing the number of scans to 256, the measurement time is increased to 8.8 minutes, but now the exceptional sensitivity reveals the carbon-13 satellites either side of the boron line. The 11B NMR spectrum of a 0.23 M solution Sodium tertraphenylborate in MeOH-d4 is shown below. A Spinsolve benchtop NMR spectrometer with a proton frequency of 60 MHz can be configured to measure the 11B NMR signal which has a frequency of 19.2 MHz. In terms of sensitivity, 11B is the better nucleus to use as it has a higher natural abundance, a higher gyromagnetic ration, and a lower quadrupole moment. Both nuclei are quadrupolar with spin of greater than ½. There are two naturally occurring NMR active nuclei of Boron, 11B (80.1%) and 10B (19.9%).
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