Determine the number of valence electrons in an argon atom.
Answer (2)
Argon is a noble gas in Group 18 of the periodic table.
Its electron configuration is 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 .
The outermost shell (third shell) contains 8 electrons ( 3 s 2 3 p 6 ).
Therefore, Argon has 8 valence electrons.
Explanation
Understanding the Problem The problem asks us to determine the number of valence electrons in an argon atom. Valence electrons are the electrons in the outermost shell of an atom, which determine its chemical properties.
Identifying Argon's Position in the Periodic Table Argon (Ar) is a noble gas, located in Group 18 (also known as Group 8A) of the periodic table. Noble gases are known for their stable electron configurations, which means they have a full outermost electron shell.
Determining Argon's Electron Configuration The electron configuration of Argon is 1 s 2 2 s 2 2 p 6 3 s 2 3 p 6 . This means it has 2 electrons in the first shell, 8 electrons in the second shell, and 8 electrons in the third shell.
Calculating Valence Electrons The outermost shell of Argon is the third shell, which contains 3 s 2 3 p 6 . Adding the number of electrons in these subshells, we get 2 + 6 = 8 valence electrons.
Final Answer Therefore, an argon atom has 8 valence electrons.
Examples
Understanding valence electrons is crucial in chemistry. For example, when designing new materials or predicting chemical reactions, knowing the number of valence electrons helps determine how atoms will interact. Argon, with its 8 valence electrons, is stable and doesn't readily form chemical bonds, making it useful in applications where inertness is required, such as in welding or lighting.
An argon atom has 8 valence electrons, which are located in its outermost shell. This is due to its electron configuration, where the outer shell contains 2 electrons from the 3s subshell and 6 from the 3p subshell. Argon's full valence shell accounts for its chemical stability as a noble gas.
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