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.” (15[1])One of these systems can transform (15[1])between different stress-induced phases when exposed to varying strain (15[1])levels, thereby displaying pseudoelasticity. (15[1])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 (-5[1])a smaller atom (10[1])replaces a larger atom’s site or sits inside a lattice’s gap (10[1])determines if these systems are substitutional or (10[1])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])