Ductile means that a substance can be drawn out into a long wire without snapping or breaking. Metals and non-metals can also be distinguished by some chemical properties. The most common chemical property is the type of oxide that the element forms.
Metals form oxides that are basic , but non-metals form oxides that are acidic. For example, sulfur and carbon are both non-metals. They react with oxygen to form sulfur dioxide and carbon dioxide. These compounds are both gases present in the air and which dissolve in rain water, making it acidic. Some oxides do not dissolve in water, so would not affect the colour of an indicator added to the water.
The element thallium forms an oxide, Tl 2 O. Thallium oxide does not dissolve in water, but does react with acids to form thallium salts. Is thallium a metal or a non-metal? Explain your answer. Thallium is a metal.
They are non-lustrous, brittle and poor conductors of heat and electricity except graphite. Non-metals can be gases, liquids or solids. Non-metals have a tendency to gain or share electrons with other atoms. They are electronegative in character. Nonmetals, when reacting with metals, tend to gain electrons typically attaining noble gas electron configuration and become anions:.
Compounds composed entirely of nonmetals are covalent substances. They generally form acidic or neutral oxides with oxygen that that dissolve in water to form acids:. As you may know, carbonated water is slightly acidic carbonic acid. Metalloids have properties intermediate between the metals and nonmetals. Metalloids are useful in the semiconductor industry. Metalloids are all solid at room temperature.
They can form alloys with other metals. Some metalloids, such as silicon and germanium, can act as electrical conductors under the right conditions, thus they are called semiconductors.
Silicon for example appears lustrous, but is not malleable nor ductile it is brittle - a characteristic of some nonmetals. It is a much poorer conductor of heat and electricity than the metals. The physical properties of metalloids tend to be metallic, but their chemical properties tend to be non-metallic.
Metallic character is strongest for the elements in the leftmost part of the periodic table, and tends to decrease as we move to the right in any period nonmetallic character increases with increasing electronegativity and ionization energy values. Within any group of elements columns , the metallic character increases from top to bottom the electronegativity and ionization energy values generally decrease as we move down a group. This general trend is not necessarily observed with the transition metals.
Mike Blaber Florida State University. Binod Shrestha University of Lorraine. Learning Objectives To understand the basic properties separating Metals from Nonmetals and Metalloids.
Metals With the exception of hydrogen, all elements that form positive ions by losing electrons during chemical reactions are called metals. Physical Properties of Metals Metals are lustrous, malleable, ductile, good conductors of heat and electricity. Other properties include: State : Metals are solids at room temperature with the exception of mercury, which is liquid at room temperature Gallium is liquid on hot days. Luster : Metals have the quality of reflecting light from their surface and can be polished e.
Malleability: Metals have the ability to withstand hammering and can be made into thin sheets known as foils. List three properties of transition metals that are different from the metals in group 1 the alkali metals.
The three main differences are:. The transition metals have the following chemical properties in common:.
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