![]() ![]() Caesium was discovered in 1860 by Robert Bunsen (he of the burner fame) and physicist Gustav Kirchhoff. Not for its eyes (it's only an element!) but less romantically for the appearance of its emission spectrum in the spectroscope. 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.Ĭaesium gets its name from the Greek for heavenly blue. 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. If it's wrong please correct me.A vertical column in the periodic table. ![]() I am not sure of how correct my knowledge is. This is the way I personally see it at least. So they would still be more active going to the left-hand side of the table. Second, assuming they could do both (lose and gain) it would still be far easier to lose 2 or 3 electrons than add like 6 more to fill the valance shell. Now intuitively it could be thought that an atom would like to have an octet of valance electrons and since most of the nonmetals are on the right-hand side of the table, the closest "octet" would be to the right, achieved by gaining electrons, and the closer it is to the right, the more it wants that electron (becomes more active like halogens).īut for metals it's the very opposite, they want to LOSE electrons because Nonmetals can do both, lose and gain electrons. Well first off metals can ONLY lose electrons, so they will always either gain a positive charge or will have a positive oxidation state. A screenshot is preferable to a picture of your laptop screen. Please do not ask for help acquiring, preparing, or handling illicit substances or for help with any activity that does not fall within the confines of whatever laws apply to your particular location.īonus points: If submitting a picture please make sure that it is clear. Any infractions will be met with a temporary ban at the first instance and a permanent ban if there is another. It is also important that you describe the specific part of the problem you are struggling with. It is OK if you are a little (or a lot!) stuck, we just want to see that you have made an effort. Please complete any questions as much as you can before posting. We will not do your homework for you, so don't ask. Please flair yourself and read over the rules below before posting. ![]()
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