A solution is defined as b) a mixture in which the substances are evenly spread out. In a solution, one substance (the solute) is dissolved in another substance (the solvent), resulting in a homogeneous mixture where the solute particles are distributed evenly throughout the solvent.
Let’s break it down further:
- Homogeneous Mixture: This means that the composition is uniform throughout. You can’t see the individual components with the naked eye.
- Solute and Solvent: The solute is the substance being dissolved (like salt or sugar), while the solvent is the substance doing the dissolving (usually water).
In contrast, options a, c, and d describe different concepts:
- a) a chemical reaction: This involves a process where substances transform into different substances, which is not what a solution is.
- c) combination of isotopes: This is related to nuclear chemistry and doesn’t pertain to solutions either.
- d) mixture in which undissolved substances do not settle out: While it hints at a colloidal mixture, it doesn’t accurately define a solution as described above.
In summary, a solution is all about being evenly mixed, and understanding this concept is essential in chemistry and various real-world applications.