Carbon chemistry
Alloy — মিশ্র ধাতু
Quick answer
A metal mixed with other elements — brass (Cu+Zn), bronze (Cu+Sn), steel (Fe+C) — for extra strength or rust resistance.
Definition
An alloy is a metallic material made by mixing a metal with one or more elements, usually to make it stronger, harder or more resistant to rust. In an alloy the added atoms sit inside the metal's structure, so it behaves like a mixture with metal bonding, not a fixed-ratio compound. Brass is copper with zinc, bronze is copper with tin, and steel is iron with a little carbon. Pure gold is soft, so jewellers add copper or silver.
For example
Rail lines across Bangladesh are steel — iron with a little carbon; many households still treasure bell-metal and brass utensils, both copper alloys.