ELE_IC Lewis Structures, Formal Charge, Resonance Structure

Valence electrons

These are the outer shell electrons of an atom which participate in chemical bonding; either transferred or involved in chemical bonding.

Lewis dot formulas or Lewis dot representations

These are convenient bookkeeping methods for tracking valence electrons.

Valence electrons

These are the outer shell electrons of an atom which participate in chemical bonding; either transferred or involved in chemical bonding.

Lewis dot formulas or Lewis dot representations

These are convenient bookkeeping methods for tracking valence electrons.

ion

This is an atom or group of atoms possessing a net electrical charge.

positive ions or cations

These atoms have lost 1 or more electrons.

negative ions or anions

These atoms have gained 1 or more electrons.

ionic bonds

These bonds are formed by the attraction between cations and anions, usually, to form solids.

ionic compounds

Commonly, metals react with nonmetals to form?

preceding noble gas

Cations become isoelectronic with the (following, preceding) noble gas.

following noble gas

Anions become isoelectronic with the (following, preceding) noble gas.

covalent bond

This is a chemical bond in which two or more electrons are shared by two atoms.

Formal charge

An atom's ________ is the difference between the number of valence electrons in an isolated atom and the number of electrons assigned to that atom in a Lewis structure.

its number of bonds and lone pairs

The number of electrons "owned" by an atom is determined by?

True.

An atom "owns" all of its unshared electrons and half of its shared electrons.

T or F?

neutral molecules

For these molecules, a Lewis structure in which there are no formal charges is preferable to one in which formal charges are present.

False. Lewis structures with large formal charges are less plausible than those with small formal charges.

Lewis structures with large formal charges are more plausible than those with small formal charges.

T or F?

electronegative atoms

Among Lewis structures having similar distributions of formal charges, the most plausible structure is the one in which negative formal charges are placed on the more ________ atoms.

resonance structures or resonance forms

Some molecules cannot be adequately represented by a single Lewis structure, these structures are called ________ in which a double-headed arrow is used to separate the two.

Two Lewis structures having the same placement of atoms but a different arrangement of electrons.

resonance hybrid

The actual structure of a molecule that is intermediate between two or more resonance structures; this shows characteristics of both resonance structures.

stability

Resonance allows certain electron pairs to be delocalized over two or more atoms, and this delocalization adds?

True.

A molecule with 2 or more resonance forms is said to be?

1. resonance structures are not real
2. resonance structures are not in equilibrium with each other
3. resonance structures are not isomers

What are the 3 basic principles of resonance theory?

resonance structures are not real

Which principle of resonance theory supports this statement?

"An individual resonance structure does not accurately represent the structure of a molecule or ion. Only the hybrid does."

resonance structures are not in equilibrium with each other

Which principle of resonance theory supports this statement?

"There is no movement of electrons from one form to another."

resonance structures are not isomers

Which principle of resonance theory supports this statement?

"Two isomers differ in the arrangement of both atoms and electrons, whereas resonance structures differ only in the arrangement of electrons."

"better" = major contributor

all the others = minor contributors

The "better" resonance structure in a hybrid is called the ________. What about all the others?

more bonds, fewer charges

A "better" resonance structure is one that has ____ bonds and ____ charges.