Valence Electrons and Chemical Bonding (9.1.1) Flashcards
• Chemical bonding involves sharing, donating, or gaining valence electrons.
• Chemical bonding involves sharing, donating, or gaining valence electrons.
• Lewis dot structures are a shorthand method for writing valence electron
configurations.
• Lewis dot structures are a shorthand method for writing valence electron
configurations.
• Elements usually react in set ratios to form neutral compounds so that each
atom has a full octet.
• Elements usually react in set ratios to form neutral compounds so that each
atom has a full octet.
Chemical bonding involves sharing, donating, or
gaining valence electrons.
Valence electrons are electrons beyond the
previous noble gas core electron configuration.
For example, the electron configuration of iron is
1s2
2s2
2p6
3s2
3p6
3d6
4s2
. The 3d6
and 4s2
electrons
in iron are beyond the argon core electron
configuration, so the 3d6
and 4s2
electrons are
valence electrons in iron.
Lewis dot structures are a shorthand method for
writing valence electron configurations.
The atomic symbol (for example, O for oxygen) is
written with one dot for each valence electron.
Since oxygen has six valence electrons, six dots are
included in the Lewis dot structure. For most
elements, eight electrons give an especially stable
configuration. This valence electron configuration is
called an octet.
Elements usually react in set ratios to form neutral
compounds so that each atom has a full octet.
For example, sodium and chlorine form an ionic
bond when one electron from sodium transfers
completely to chlorine. The result is a chloride ion
with eight valence electrons (an octet), and a
sodium ion with zero valence electrons (in effect,
the previous shell has become the valence shell of
sodium—so sodium has a full octet). The two ions
form an ionic bond, and react in a one-to-one ratio
to form an ionic compound.
A covalent bond is formed by the sharing of
electrons between two atoms. For example, two
atoms of iodine react to form a molecule of
diiodine. Two of the electrons are shared, so each
atom effectively has eight valence electrons (an
octet).
Chemical bonding involves sharing, donating, or
gaining valence electrons.
Valence electrons are electrons beyond the
previous noble gas core electron configuration.
For example, the electron configuration of iron is
1s2
2s2
2p6
3s2
3p6
3d6
4s2
. The 3d6
and 4s2
electrons
in iron are beyond the argon core electron
configuration, so the 3d6
and 4s2
electrons are
valence electrons in iron.
Lewis dot structures are a shorthand method for
writing valence electron configurations.
The atomic symbol (for example, O for oxygen) is
written with one dot for each valence electron.
Since oxygen has six valence electrons, six dots are
included in the Lewis dot structure. For most
elements, eight electrons give an especially stable
configuration. This valence electron configuration is
called an octet.
Elements usually react in set ratios to form neutral
compounds so that each atom has a full octet.
For example, sodium and chlorine form an ionic
bond when one electron from sodium transfers
completely to chlorine. The result is a chloride ion
with eight valence electrons (an octet), and a
sodium ion with zero valence electrons (in effect,
the previous shell has become the valence shell of
sodium—so sodium has a full octet). The two ions
form an ionic bond, and react in a one-to-one ratio
to form an ionic compound.
A covalent bond is formed by the sharing of
electrons between two atoms. For example, two
atoms of iodine react to form a molecule of
diiodine. Two of the electrons are shared, so each
atom effectively has eight valence electrons (an
octet).
Which one of the following compounds would you expect to be covalent?
OF2 (B)
The electron configuration of an oxygen atom is 1s 22s 22p 4. How many valence electrons does an oxygen atom have?
6 (C)
The electron configuration of Li + ion is 1s 2. How many valence electrons are found in the Li + ion?
none (C)
How many valence electrons does Na+ have?
0 (C)
Which of the following is the correct Lewis dot structure for carbon dioxide?
(A)
How many valence electrons does Na have?
1 (D)
Which of the following best represents the Lewis Dot structure of nitrogen?
(B)
The electron configuration for sulfur is 1s 22s 22p 63s 23p 4. How many valence electrons does a sulfur atom have?
6 (A)
How many valence electrons are found in an atom of nitrogen?
5 (C)
Which of the following is a reasonable Lewis Dot symbol for a fluorine atom?
(C)
