102

Unit 1
Elements of Chemical Structure and Inorganic Nomenclature

1-2. Matter and Energy

Matter is anything that occupies space and has weight. If you look around you, you will see matter. The table, books, walls, and your body are all composed of matter. Obviously, the matter around you is not all the same.

Physical States of Matter. In general, we can group all matter into three groups called states of matter.

Properties of Matter. Matter possesses two types of properties, physical and chemical. Characteristics such as smell, color, shape, freezing point, boiling point, and solubility are said to be physical properties of matter. Energy content, reactions with other substances, and chemical reactions due to light, heat, and electricity are said to be chemical properties of matter. From the physical and chemical properties exhibited by a substance, it is possible to isolate, identify, and classify the particular substance.

Classification of Pure Matter. Matter that cannot be separated into two or more types of matter by physical means is called pure matter. Pure matter consists of two types, elements and compounds.

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Table 1-1. Elements, symbols, atomic numbers, and atomic Weights in alphabetical order.

Classification of Mixed Matter. Matter that can be separated by physical means is called mixed matter and may be homogeneous or heterogeneous.

ENERGY

There are many things in our surroundings that we know exist, yet are not matter. They are forms of energy. Heat, light, and electricity are examples of energy. Energy may be simply defined as the ability to do work or overcome resistance.