Chemical and Physical Matter and its Properties.

Matter and its Properties

Basic Building Blocks of Matter

The fundamental building blocks of matter are atoms and molecules. These make up elements and compounds. An atom is the smallest unit of an element that maintains the properties of that element. And element is a pure substance made of only one kind of atom. A compound is the substance that is made from the atoms of two or more elements that are chemically bonded. Water is an example of a compound because it is one of many compounds that consist of molecules. The hydrogen and oxygen molecules are chemically bonded to form a water molecule.

Properties and Changes in Matter

Every substance, whether an element or compound, has characteristic properties. Chemists use these properties to distinguish different substances and then use their knowledge of characteristics to separate them.

A property may be a characteristic that defines an entire group of substances.

Chemical substance

Rainbow of chemicals

Dangerous substance(危険物)

That property can be used to classify an unknown substance within that group. For example, are large groups of elements is metals. The property that sets than apart from anything else is that they conduct electricity well. Therefore, if scientists find an unknown element, and test it for electricity conduction, and it turns out to conduct electricity well, it is, in fact, a metal.

Properties also define subgroups or substances. And can also help to reveal the identity of an unknown substance. However, identification usually cannot be made based on only one property. Comparisons of several properties can be used to determine the identity of an unknown. Properties are either intensive or extensive. An extensive property depends on the amount of matter that is present. These properties include volume, mass, and the amount of energy in a said substance. Intensive properties, however, do not depend on the amount of...