From da602f2cdc26683a6f92a2cb1d22e00c2cc01ec3 Mon Sep 17 00:00:00 2001 From: eggy Date: Thu, 8 Oct 2020 22:06:38 -0400 Subject: [PATCH] chem: fix and clarify formal charges --- docs/sch3uz.md | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/docs/sch3uz.md b/docs/sch3uz.md index 2a4ebed..3f44798 100644 --- a/docs/sch3uz.md +++ b/docs/sch3uz.md @@ -318,10 +318,10 @@ There may be several correct ways to draw covalent bonds in Lewis structures and The formal charge of an atom can be calculated using the following equation: $$\text{Formal charge} = \text{# of valence electrons of element} - \text{# of unpaired electrons} - \text{# of covalent bonds}$$ -To find the best structure for a covalently bonded compound, the formal charge of all atoms in that compound should be **minimised**. +To find the best structure for a covalently bonded compound, the **absolute value** of the formal charge of all atoms in that compound should be **minimised**. Positively charged atoms will even accept **dative covalent bonds** from other atoms with negative formal charges. !!! warning - Some elements want formal charges of zero so much that they break the octet rule. These elements are $\text{P, S, Cl, Br, I, and Xe}$. To do so, they will accept **dative covalent bonds** from other atoms with opposite formal charges. This brings the formal charges of both atoms closer to zero by one. + Some elements want formal charges of zero so much that they break the octet rule. These elements are $\text{P, S, Cl, Br, I, and Xe}$. ### Resonance structures