Matter

Matter is defines as anything that occupies space and has mass. Mass is the quantity of matter which a substance possesses and, depending on the gravitational force acting on it, has a unit of weight assigned to it. Although the weight then can vary, the mass of the body is a constant and can be measures by its resistance to a change of position or motion. This property of mass to resist a change f position or motion is called inertia. Since matter does occupy space, we can compare the masses of various substances that occupy a particular unit volume. This relationship of mass to a unit volume is called the density of the substance. It can be shown in a mathematical formula as:

D = m / V

The basic unit of mass (m) in chemistry is the gram (g), and of volume (V) is the milliliter (ml)

Matter occurs is three states: solid, liquid, and gas. A solid has both a definite size and shape. A liquid has a definite volume, but takes the shape of the container and a gas ha neither a definite shape nor a definite volume. The states of matter can be changes by the addition of heat energy.

ex.: Ice changes to water, which the will change to water vapor, or steam.

Matter can be subdivided into two general categories: distinct substances and mixtures. The distinct substances are either elements or compounds. If a substance is made up of only one kind of atom, it is called an element. If, however, it is composed of two or more kinds of atoms joined together in a definite grouping, it is classified as a compound. That a compound then always occurs in a definite composition is called the Law of Definite Composition or Proportion.

ex.: Water (H2O) always occurs in a two hydrogen, one oxygen relationship

Mixtures, on the other hand, have an indefinite composition, such as the heterogeneous mixture of marble. In a mixture, the properties of the constituent ions are retained. And the parts of the Mixture react differently to changed conditions.

Chemical Properties

Physical properties of matter are those that can be usually observed with our senses. They include everything about a substance that can be noted when no change is occurring in the type of structure that makes up its smallest component. Some common examples are physical states, colors, odors, solubilities in water, densities, melting points, tastes, boiling points, and hardness.

Chemical properties are those properties which can be observed in regard to whether or not a substance reacts with other substances. Some common examples are: iron rusting in moist air, nitrogen does not burn, gold does not rust, and sodium reacts with water.

When ordinary chemical changes occur, the mass of the reactants equal the mass of the products. This can be created nor destroyed, but only changed from one form to another. This is referred to as the Law of Conservation of Matter (Lavoisier-1785). This law is contradicted by the Einstein mass-energy relationship, which states that matter and energy are interchangeable.