Matter and Its Interactions
Matter is all around us, from the air we breathe, to the food we eat. It consists of atoms and molecules that interact in different ways. The knowledge of the properties of the matter, states in which it is present, and the methods of its transformations between the states is crucial for science.
1. Mixtures
Mixtures refer to combinations of two or more substance with each substance retaining its distinct properties. There exist two types of mixtures, namely;
Heterogeneous Mixtures:
In these mixtures, the constituents are not uniformly distributed and you find it easy to see or to separate the parts.
Examples: Salad, sand and water, granite.
Homogeneous Mixtures:
The parts are distributed equally and you can’t determine which one is from the other one.
Examples: Saltwater, air, and solutions.
Properties:
Mixtures do not have any definite composition.
Components can be isolated with the help of physical mechanisms (filtering, distillation etc.).
2. States of Matter
Matter is in three main states. solid, liquid, and gas. Such a status relies on organization and motion of molecules.
Solids:
Molecules are close packed and vibrate where they are.
They have the same shape and volume.
Examples: Ice, wood, metal.
Liquids:
Molecules are close to each other but can slip past each other.
Liquids take up fixed volume but no fixed shape. They adopt the form of what they are being contained i.e. their container.
Examples: Water, oil, juice.
Gases:
Molecules are far away from each other and can move freely.
Gases have no definite shape and volume and will fill any given space.
Examples: Air, oxygen, carbon dioxide.
3. Phase Changes
Phase changes involve when we have change to another state of matter in an attempt to change the temperature or pressure. These changes are physical and no change in substance’s composition occurs.
Types of Phase Changes:
Melting: Solid into a liquid (for example, like ice turning into water).
Freezing: Liquid to solid (for example, water turns into ice).
Vaporization: Conversion from liquid to gas (boiling of water to convert to steam).
Condensation: Conversion of gas to liquid, for example, gas condensing at a cold surface.
Sublimation: Solid to gas without going through the stage of becoming a liquid (e.g. dry ice transforming straight into carbon dioxide gas).
Deposition: Gas to solid while without becoming a liquid (like frosting over a cold surface).
Energy in Phase Changes:
Energy is either absorbed or given out when phase changes occur. For instance, heat is gained on melting and boiling while it is lost while freezing and condensation occurs.