Alloys are useful (if this is what the question is getting at) because mixing elements of the periodic table alters their colligative properties.
i.e. mixing two metals could change substance's melting point, allowing it to more easily resist high temperatures. Also, mixing metals can change the way they bind together, and create an altogether stronger material than you can find using any single metal alone.They can improve a metal's properties
Progressives were interested in establishing a more transparent and accountable government which would work to improve U.S. society. These reformers favored such policies as civil service reform, food safety laws, and increased political rights for women and U.S. workers.
All chemical bonds, including those found in network solids, derive from the electromagnetic force. Positively charged protons attract negatively charged electrons. Although atoms start off with an equal number of protons and electrons, and are therefore electrically neutral, the electrons rearrange themselves in ways that create attractions between atoms. Covalent bonds
Temperature and Pressure
Metals higher in the series will replace metal ions in solution that are lower in the series
ions
A superconductor.
Molecular solids
Dirt is a heterogeneous mixture.