It is not easy to define what a metal is. Physically, a metal is a substance that has a bright luster and is a good conductor of heat and electricity. Metals have varying degrees of hardness, density, malleability and ductility. (Malleability concerns being able
to be rolled Out and hammered. Ductility has to do with being drawn out, as into wire.)
Metal has a definite melting point and will fuse with other metals to form "alloys". With the exception of mercury, all metals are solids at ordinary temperatures.
Some metals are found in the pure state, but most of them are found in combination with other elements. These metals arc in the form of sulphides, oxides, carbonates, and silicates, usually mixed with rock and earthy materials. Some of the common metals found in combination in ores are lead, zinc, iron, copper, chromium, nickel, and mercury.
Some metals are so rare that tons of ore must be treated to get even a small amount of the pure metal. Radium is one of these. The science of recovering metals from their ores is called ''metallurgy".
Many metals, when they are in the pure state, have properties that are undesirable. This is why most of the metals commonly used today are either alloys or compounds. Examples of alloys are table silver, gold coins, and aluminium pans. Pure iron is too soft to be of much value, so it is used most frequently as steel, which is a compound.There are a few metals which, in tiny amounts, are necessary to animal life. Among these are iron, potassium, calcium, magnesium, and sodium. The body even uses minute quantities of copper, aluminium, and manganese
to be rolled Out and hammered. Ductility has to do with being drawn out, as into wire.)
Metal has a definite melting point and will fuse with other metals to form "alloys". With the exception of mercury, all metals are solids at ordinary temperatures.
Some metals are found in the pure state, but most of them are found in combination with other elements. These metals arc in the form of sulphides, oxides, carbonates, and silicates, usually mixed with rock and earthy materials. Some of the common metals found in combination in ores are lead, zinc, iron, copper, chromium, nickel, and mercury.
Some metals are so rare that tons of ore must be treated to get even a small amount of the pure metal. Radium is one of these. The science of recovering metals from their ores is called ''metallurgy".
Many metals, when they are in the pure state, have properties that are undesirable. This is why most of the metals commonly used today are either alloys or compounds. Examples of alloys are table silver, gold coins, and aluminium pans. Pure iron is too soft to be of much value, so it is used most frequently as steel, which is a compound.There are a few metals which, in tiny amounts, are necessary to animal life. Among these are iron, potassium, calcium, magnesium, and sodium. The body even uses minute quantities of copper, aluminium, and manganese
