Presentation on theme: "Nonmetals, inert gases, and semimetals Exploring the right side of the periodic table."— Presentation transcript:
Nonmetals, inert gases, and semimetals Exploring the right side of the periodic table.
Properties of non metals Nonmetals lack the properties of metals. Most nonmetals are poor conductors of both heat and electricity. Nonmetal solids are brittle and are dull in color. (Sulfur) Many nonmetals are common Earth elements.
Physical properties Four nonmetals are gases at room temperature (oxygen, nitrogen, fluorine, and chlorine). Other nonmetals are solids at room temperature (carbon, iodine, and sulfur). Bromine is the only nonmetal which is a liquid at room temperature.
Chemical properties Atoms of nonmetals either gain or share electrons when they react with other elements. Examples of these types of reactions are salt (NaCl) and rust (Fe 2 O 3 ).
Families of the Non metals (The Boron Family) These elements usually share or donate their three electrons in the valence shell. The family extends from Boron to Ununtrium (#113). One of the most commonly used elements from this family is Aluminum.
(The carbon family) The elements in the carbon family all like to share, gain, or lose four electrons. The Family extends from carbon through lead. Carbon is the basis of all of the life on the planet Earth.
Why is Carbon so important to life on planet Earth? Because carbon has the unique ability of being the only nonmetal which can generate four bonds it can form long chains to produce many different substances. Proteins, oil, carbohydrates, and coal are examples of important substances which are made of long chains of carbons.
The nitrogen family This group contains two nonmetals nitrogen and phosphorous, which are both important to plants and agricultural growth. The elements in this family usually share or gain three electrons. The Earths atmosphere is about 80% nitrogen gas. Nitrogen occurs in nature as N 2 which is called a diatomic molecule. In this form the N 2 gas is not very reactive. Some bacteria use nitrogen as the basis to form compounds to keep themselves alive (Nitrogen fixation). Match heads are made of phosphorous which is very reactive when struck and lit.
The oxygen family The oxygen family contains three nonmetals (oxygen, sulfur, and selenium). These elements usually gain or share two electrons. Oxygen is one of the most important elements which keeps the human species alive. Oxygen, like nitrogen is a diatomic molecule (O 2 ), and can also form a triatomic molecule (O 3 ) called ozone. Oxygen is very reactive and can combine with most other elements. Oxygen is the most abundant element in the Earths crust and the second most abundant in the atmosphere. Sulfur which is another member of the Oxygen family which is used to make Sulfuric acid (H 2 SO 4 )
The halogen family Group 17 contains fluorine, chlorine, bromine, iodine, and astatine. Halogen actually means “salt forming” Halogens gain or shares only one electron with other elements to make compounds. Halogens are very dangerous when in a pure form. Example of dangerous halogens are bromine which can cause significant burns, bromine also reacts with silver to produce photos and images on x- ray film.
Inert gases The elements in group 18 are the inert gases. The other name for the inert gases are the “noble gases” These gases do not usually share, gain, or lose any electrons. The inert gases tend to be very unreactive. These gases are so unreactive they were not discovered until the late 1800s’. Common uses for noble gases are neon signs (also xenon, and argon). Also helium is used in helium balloons.
Hydrogen Hydrogen lacks a neuron and contain only one proton. Although it makes up 90% of the universe, it actually makes up less that 1% of the Earths crust. Most hydrogen is bound to oxygen to produce water. Because hydrogen has some unique properties it is not placed in a particular group. Hydrogen can combine with most every other element, so it is reactive, but it is a gas, so it is placed in the far left corner of the periodic table by itself.
Semimetals Semimetals are between metals and nonmetals. These elements have characteristics of both groups. The most common metal is silicon (Si). The most common place to find silicon is at the beach which is silicon dioxide or SiO 2, which is called sand. Semimetals are semiconductors which means they conduct electrical current under certain conditions. The semiconduction characteristic of the semimetals is the reason why elements like Silicon and Gemanium are used for computer chips, lasers, and transistors.