In 2010, Senkov et al. created the first refractory RHEA (“R-H-E-A”) kind of these systems, which themselves are based on another one of these systems described as “high-entropy.” One of these systems can transform between different stress-induced phases when exposed to varying strain levels, thereby displaying pseudoelasticity. The identity of these systems, which often depends on whether one quantity for a constituent is 15% larger than the other, can be predicted via the (*) Hume-Rothery rules. Nitinol is an example of one of these systems exhibiting “shape memory.” (10[1])Whether a smaller (-5[1])atom replaces a larger atom’s site or sits inside a lattice’s gap determines if these systems are substitutional or interstitial. Amalgams are one of these systems mainly made of mercury. For 10 points, name these solid solutions composed of two or more different metals. ■END■ (10[1])