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The gas constant R is defined as the Avogadro constant N A multiplied by the Boltzmann constant k (or k B): = = 6.022 140 76 × 10 23 mol −1 × 1.380 649 × 10 −23 J⋅K −1 = 8.314 462 618 153 24 J⋅K −1 ⋅mol −1. Since the 2019 revision of the SI, both N A and k are defined with exact numerical values when expressed in SI units. [2]
lower octane gas can be sold if labeled as "sub-standard" or "sub-regular" [11] South Dakota: 85/87 87/89 91 85 octane must be sold with a warning label displayed at the pump. [12] 85 and 86 octane can be sold as regular fuel only in the counties of Butte, Custer, Fall River, Harding, Lawrence, Meade, Oglala Lakota, Pennington, and Perkins.
226 Ra occurs in the decay chain of 238 U (often referred to as the radium series). Radium has 34 known isotopes from 201 Ra to 234 Ra. In the early history of the study of radioactivity, the different natural isotopes of radium were given different names, as it was not until Frederick Soddy 's scientific career in the early 1900s that the ...
Standard sea-level conditions (SSL), [1] also known as sea-level standard (SLS), defines a set of atmospheric conditions for physical calculations. The term "standard sea level " is used to indicate that values of properties are to be taken to be the same as those standard at sea level, and is done to define values for use in general calculations.
It consists of an open- topped cylindrical steel shell equipped with a roof that floats on the surface of the stored liquid. The roof rises and falls with the liquid level in the tank. [1] As opposed to a fixed roof tank there is no vapor space in the floating roof tank (except for very low liquid level situations). In principle, this ...
Similar to the Kelvin scale, which was first proposed in 1848, [1] zero on the Rankine scale is absolute zero, but a temperature difference of one Rankine degree (°R or °Ra) is defined as equal to one Fahrenheit degree, rather than the Celsius degree used on the Kelvin scale.
Gas flow can be grouped in four regimes: For Kn≤0.001, flow is continuous, and the Navier–Stokes equations are applicable, from 0.001<Kn<0.1, slip flow occurs, from 0.1≤Kn<10, transitional flow occurs and for Kn≥10, free molecular flow occurs. [6] In free molecular flow, the pressure of the remaining gas can be considered as effectively ...
There are 39 known isotopes of radon (86 Rn), from 193 Rn to 231 Rn; all are radioactive.The most stable isotope is 222 Rn with a half-life of 3.8235 days, which decays into 218 Po