Bonds & ions
Cation — ক্যাটায়ন
Quick answer
A cation is a positively charged ion, formed when an atom or molecule loses one or more electrons.
Definition
A cation is an ion with a positive charge, made when an atom or molecule loses one or more electrons, leaving protons in the majority. Metals form cations easily, which is why they sit on the left of the periodic table and react by electron loss: sodium becomes Na⁺, calcium Ca²⁺, iron Fe²⁺ or Fe³⁺. With the same nuclear pull now holding fewer electrons, cations are smaller than the atoms they come from, and during electrolysis they migrate to the negative electrode.
For example
In your school's copper-plating experiment, Cu²⁺ cations drift toward the negative electrode and settle as a fresh pink-brown layer of copper on the spoon.