Halogens, located in group 17 of the periodic table, are elements with seven valence electrons predisposing them to form anions. This text delves into their physical states—gaseous fluorine and chlorine, liquid bromine, and solid iodine—and their increasing melting and boiling points from fluorine to iodine. It discusses their high reactivity, especially fluorine, and their applications in daily life, such as disinfectants and pharmaceuticals, while also touching on environmental concerns like the ozone-depleting effects of some halogen compounds.
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Halogens are a group of elements with seven valence electrons in the outermost p-subshell, known for their tendency to form anions with a -1 charge
Elements in Group 17
The elements in Group 17 include fluorine, chlorine, bromine, iodine, and astatine, with tennessine sometimes considered part of the group
Characteristics of Group 17 Elements
Group 17 elements are nonmetals with poor conductivity, varying states at room temperature, and a range of colors
The physical properties of halogens, such as melting and boiling points, are affected by their atomic radius and number of electrons
Halogens are highly reactive, especially in forming anions and engaging in reactions such as salt formation and hydrogen halides
Trends in Electronegativity
Electronegativity decreases down the group, with fluorine being the most electronegative element in the periodic table
Trends in Electron Affinity
Electron affinity generally decreases down the group, but fluorine's electron affinity is lower than chlorine's due to electron repulsion
Bond enthalpies for halogen-halogen and hydrogen-halogen bonds decrease down the group
Halogens have diverse applications in daily life, such as disinfectants, lighting, and pharmaceuticals
Health Benefits
Halogens, such as fluoride and iodine, have health benefits such as preventing dental cavities and promoting thyroid health
Environmental Concerns
Some halogen compounds, like chlorofluorocarbons, have been regulated due to their negative impact on the ozone layer
00
The halogens, located in group ______ of the periodic table, include elements like ______ and ______.
17
fluorine
chlorine
01
Halogens conductivity and brittleness
Poor heat and electricity conductors; typically brittle in solid state.
02
Halogens state at room temperature
Fluorine and chlorine are gases, bromine is liquid, iodine is solid.
