1. Mercury(I) or mercurous ion is Hg22+.
QUESTION:
Which of the following is the correct formula for the mercury(I) ion? A. Hg, B. Hg2, C. Hg+, D. Hg22+
Mercury(I) or mercurous ion is Hg22+.
Mercury(II) or mercuric ion is Hg2+.
Why is Hg22+ called mercury(I). Because the pair has a total charge of +2, it’s as if each Hg has a charge of is NOT the charge of Hg atoms in mercury(I); it’s the “oxidation number” or “oxidation state”
Memorize: two polyatomic ions in ionic compounds, the other is ammonium (NH4+)
All other transition metal ions are monatomic. Examples: Copper(I) is Cu+, lead (IV) is Pb4+
SCRIPT:
Which of the following is the correct formula for the mercury one ion? Hg…
Hg with a subscript of 2…
Hg with a superscript of +…. Or
Hg with a subscript of 2 and a superscript of 2+
PAUSE CLICK The correct answer is D. Mercury on is an ion consisting of two covalently-bonded mercury atoms, with an overall charge of –2.
CLICK
It’s one of only two naturally –occurring ions of mercury. The other naturally-occurring ion of mercury is mercury two, or mercuric ion, which is monatomic.
CLICK If you’re wondering why a pair of mercury atoms with an overall charge of –2 is called mercury one---- the reason is that because the pair has an overall charge
of –2, it’s as if each atom in the pair has a charge of +1.
CLICK We do NOT refer to +1 as the charge of the mercury atoms here. +1 is called the oxidation number, or oxidation state.
Mercury one is one of only two polyatomic ions you’ll encounter as part compounds. So it’s good to memorize it.
The other one that should memorize is ammonium, which has a formula of NH4 plus.
HIGHLIGHT
All other transition metal ions are monatomic, so if you see a roman numeral indicated next to the name of a transition metal, it should it should be easy to determine the symbol
CLICK For example, copper one is Cu with a +1 charge,…
HIGHLIGHT and lead four is Pb with a +4 charge.
CLICK PAUSE END RECORDING

2. Video ID: © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Narrator: Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08