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 (15[1])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.” Whether a smaller atom replaces a larger atom’s (10[1])site or sits inside a lattice’s gap determines if these systems are substitutional or interstitial. Amalgams (10[1])are one of these systems mainly made of mercury. For 10 points, name these solid solutions composed of two or more different metals. ■END■