Chemistry: matter and the divisions of matter
Matter is everything around you. It’s the food you eat, the air you breathe, and the clothes you wear. Even you are made of matter. Therefore, it is necessary to know the different types, shapes and properties of matter.
Matter is anything that has mass and volume. Mass is the amount of inertia in matter and volume is the amount of space occupied by matter. Inertia is the resistance to change and the greater the inertia, the greater the mass.
DIVISIONS OF MATTER
Matter is often divided into two categories: pure substances and mixtures. It is important that you can distinguish one form of matter from another so that you can describe the changes you observe.
Pure substances They consist of a material with a defined composition and defined properties. Pure substances are divided into two groups: elements and compounds.
Elements are the simplest forms of chemicals and cannot be broken down by ordinary chemical means. Examples would be hydrogen (H), sulfur (S), or gold (Au). The simplest form of an element is an atom.
Compounds are chemical combinations of elements that can be described with a chemical formula and can only be separated by chemical means. Examples of compounds are water, sugar, and salt. The simplest forms of a compound are molecules or units of the formula.
MIXTURES
Mixes are all around you. A salad is a mixture of vegetables, a glass of soda is a mixture of water, sugar, and flavorings, and air is a mixture of gases such as nitrogen, oxygen, and carbon dioxide.
Mixtures are physical combinations of two or more substances with varying compositions, varying properties, and can be separated by ordinary physical processes. In general, mixtures are divided into two large groups: homogeneous and heterogeneous.
Homogeneous mixtures they are the same at all times and do not phase separate when left alone. Many homogeneous mixtures are solutions that consist of a solute and a solvent. The solute is the material that dissolves and the solvent is the material that causes the dissolution. The solutions are completely dissolved and clear.
An alloy is a solution of two or more elements, at least one of which is a metal, where the resulting material has metallic properties. Alloys are often made to improve the properties of the elements that compose them. Steel, for example, is much stronger than iron, which is its main component.
Heterogeneous mixtures do not have a defined composition and separate into phases when left alone. Heterogeneous mixtures can be separated by ordinary physical means. Examples of mixed bag mixes are blood, Italian salad dressing, and soft drinks.
Another type of mixture is a colloid. A colloid is a suspension that does not separate because the particles do not dissolve completely and remain suspended, which makes the mixture appear cloudy. This cloudiness, called the Tyndall effect, is due to the scattering of light by suspended particles.
A solution does not scatter light because the particles are at the molecular level and are too small to reflect light. However, colloidal particles are large enough to reflect light and small enough not to settle. The scattering of light from car headlights in fog and a beam of light by dust particles are examples of the Tyndall effect.
Colloids They are formed from all combinations of solids, liquids or gases (except gas mixtures that do not react, which are true solutions). Aerosols, foams, emulsions, and soils are different types of colloids. Examples of colloids are shaving cream, whipped cream, and gelatin.