Nickel radii

Yttrium, on the otlrer hand, which has a larger cation radius than Cr +, appears to affect the grain boundary cation diffusion and not the volume diffusion of Ni +. The effects of the addition of small amounts of yttrium to nickel is to decrease dre rate of tire low temperamre grain-boundary dominated oxidation kinetics. 

Nickel has an atomic radius of 0.162 nm. The edge of its cubic unit cell is 0.458 nm. What is the geometry of the nickel unit cell ... 

Calculate the density of each of the following metals from the data given (a) nickel, fee structure, atomic radius 125 pm (b) rubidium, bcc structure, atomic radius 250 pm. 

Identify- the element with the larger atomic radius in each of the following pairs (a) iron and nickel (b) copper and silver ... 

The radii in the lowest row of the table were obtained by a number of approximate considerations. For instance, if we assume the bismuth radius to bear the same ratio to the interatomic distance in elementary bismuth as in the case of arsenic and antimony, we obtain (Bi) = 1.16— 1.47 A. A similar conclusion is reached from a study of NiSb and NiBi (with the nickel arsenide structure). Although the structures of the aurous halides have not been determined, it may be pointed out that if they are assumed to be tetrahedral (B3 or Bi) the interatomic distances in the chloride, bromide, and iodide calculated from the observed densities1) are 2.52, 2.66, and 2.75 A, to be compared with 2.19, 2.66, and 2.78 A, respectively, from pur table. 

The curve of single-bond metallic radii for the elements of the first long period has a characteristic appearance (Fig. 3) which must be attributed in the main to variation in the type of bond orbital. The rapid decrease from potassium to chromium results from increase in bond strength due to increasing s-p and d-s—p hybridization. The linear section of the curve from chromium to nickel substantiates the assumption that the same bonding orbitals (hybrids of 2.56 3d orbitals, one 4s orbital, and 2.22 4p orbitals) are effective throughout this series. The increase in radius from nickel to copper is attributed not... 

However, consideration in terms of the ionic radius or the LFSE shows that both factors predict that the maximum stabilities will be associated with nickel(ii) complexes, as opposed to the observed maxima at copper(ii). Can we give a satisfactory explanation for this The data presented above involve Ki values and if we consider the case of 1,2-diaminoethane, these refer to the process in Eq. (8.13). 

Derived from the German word meaning devil s copper, nickel is found predominantly in two isotopic forms, Ni (68% natural abundance) and Ni (26%). Ni exists in four oxidation states, 0, I, II, III, and IV. Ni(II), which is the most common oxidation state, has an ionic radius of —65 pm in the four-coordinate state and —80 pm in the octahedral low-spin state. The Ni(II) aqua cation exhibits a pAa of 9.9. It forms tight complexes with histidine (log Af = 15.9) and, among the first-row transition metals, is second only to Cu(II) in its ability to complex with acidic amino acids (log K( = 6-7 (7). Although Ni(II) is most common, the paramagnetic Ni(I) and Ni(III) states are also attainable. Ni(I), a (P metal, can exist only in the S = state, whereas Ni(lll), a cT ion, can be either S = or S =. ... 

The viscosity of molten BeF2 and LiF-BeF2 mixture has been measured with this method. In this experiment, cylindrical spindles of Inconel, varying in radius between 0.158 and 1.65 cm, were rotated in nickel vessels of 2.05 cm internal radius. 

Optimizing a MM model (MOMEC95, force field396) with regard to axial Ni - -11 and Ni C interactions in a set of structurally characterized bis(diamine)nickel(II) complexes has allowed the deduction of a van der Waals radius for low-spin Ni11 of 1.35 A.3... 

The larger bite angles of the C3-bridged ligands preclude the ligand-exchange equilibrium, the ionic radius of the nickel(II) ion being too small to accommo-... 

Reduction lowers the charge to radius ratio of transition metal ions, promoting higher rates of ligand substitution. Reduced, divalent oxidation states of manganese, iron, cobalt, and nickel are also quite soluble (Table II). 

Deposition of metals around the large Copper Cliff smelter in Sudbury, Ontario, is a significant local problem. It is estimated that 42% of nickel particulates emitted from the 381-m stack are deposited within a 60-km radius of the smelter (Taylor and Crowder 1983). The Copper Cliff smelter, one of three large nickel sources in the Sudbury area, emits 592 pounds (269 kg) of nickel a day. 

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