A homogeneous mixture has a uniform composition. They are usually made of small particles, such as atoms and molecules, that are evenly distributed.
For example, water mixed with hydrogen is a homogeneous mixture. This is because no matter which area of the mixture you look at, you will see water molecules and hydrogen molecules. Therefore, the mixture’s composition is uniform.
Figure 1 - A homogeneous mixture of water and hydrogen. Hydrogen is represented by the two small blue circles connected together. Water is represented by the red circle connected to the two smaller circles.