8.1. Ions http://www.ck12.org
FIGURE 8.2
Neon atoms and sodium ions are isoelec-
tronic. Neon is a colorless and unreactive
gas that glows a distinctive red-orange
color in a gas discharge tube. Sodium
ions are most commonly found in crystals
of sodium chloride, which is the chemical
name for ordinary table salt.MEDIA
Click image to the left for more content.- How does this song compare an outer energy level with eight electrons to emotions? 2. What are the two
exceptions to the octet rule in this song?
Transition Metal Ions
Transition metals belong to thedblock, meaning that thedsublevel of electrons is in the process of being filled with
up to 10 electrons. Many transition metals cannot lose enough electrons to attain a noble gas electron configuration.
Additionally, you have learned that the majority of transition metals are capable of adopting ions with different
charges. Iron, which can form either Fe^2 +or Fe^3 +ions, loses electrons, as shown below.
Fe → Fe^2 ++ 2 e−
[Ar]3d^64 s^2 [Ar]3d^6Fe → Fe^3 ++ 3 e−
[Ar]3d^64 s^2 [Ar]3d^5According to the Aufbau process, the electrons fill the 4ssublevel before beginning to fill the 3dsublevel. However,
the outermostselectrons are always the first to be removed when forming transition metal cations. Because most
transition metals have two valence electrons, a charge of 2+ is very common for transition metal ions, as we have
already seen in the case of iron. A half-filleddsublevel (d^5 ) is also particularly stable. This type of configuration is
obtained when an iron atom loses a third electron.
Some transition metals that have relatively fewdelectrons, such as scandium, may be able to attain a noble gas
electron configuration.
Sc → Sc^3 ++ 3 e−
[Ar]3d^14 s^2 [Ar]