Section 1: Matter

Ions, Mixtures, and Solutions

The properties of hydrogen and oxygen are changed when they combine to make water. It is likely that everything around you is a type of compound. A reaction occurs when two or more molecules interact and something happens. The change that occurs when this reaction happens can be described by chemical properties. An example of a chemical reaction is when a car rusts. Why does this happen? It is due to the iron (Fe) in the metal interacting with water and oxygen in the atmosphere, resulting in rust. A reaction can happen with anything, including molecules, individual atoms, or ions. Ions are atoms that have lost or gained an additional electron, although atoms are usually neutral, as discussed earlier. A negatively charged ion has extra electrons and a positively charged ion has fewer electrons than protons. Ions are attracted to each other when they have opposite charges. An example that you should be familiar with is when a sodium (Na) atom loses an electron and becomes attracted to a chlorine (Cl) atom that has extra, which creates table salt.

When many different objects are mixed together, but they all retain their individual properties, it is called a mixture. An example of a mixture may be your pencil or a folder. Many people think of soda or lemonade as a mixture. That is also correct. The difference is that these are examples of a type of mixture called a solution. A solution is formed when one substance of a mixture dissolves in another substance, such as the lemonade that you drink on a hot summer day. Another property of a solution is that one part of the solution is the same as all the other parts. By stirring the lemonade into the water, you spread the molecules evenly.

Drag and Drop

Section 1, Part L