Covalent Bonds and Lewis Structures Lecture Review

Flashcards covering key vocabulary related to covalent bonding, Lewis structures, and chemical nomenclature from the lecture notes.

Covalent Bond

A chemical bond where two atoms share two electrons, represented by a line in a Lewis structure.

Dot Structure

A drawing that shows the valence electrons of an individual atom or in a molecule, using dots around the atom symbol.

Valence Electrons

The outermost electrons of an atom that participate in bonding, represented by dots in a dot structure.

Lone Pair

A pair of electrons on an atom that are already together and not involved in forming a bond; they are 'happy' in their pair.

Octet

The goal for most atoms to have eight valence electrons in their outermost shell to achieve stability, similar to noble gases.

Hydrogen's Electron Stability

Hydrogen aims to have two electrons to be stable, unlike other atoms that mostly seek an octet.

Double Bond

A covalent bond represented by two lines between atoms, indicating that four electrons (two pairs) are being shared.

Triple Bond

A covalent bond represented by three lines between atoms, indicating that six electrons (three pairs) are being shared.

Central Atom

In a Lewis structure, the atom that typically forms the most bonds, usually listed first in the chemical formula (hydrogen is rarely the central atom).

Naming Rule: No 'Mono' for First Element

In naming covalent compounds, the prefix 'mono' is not used for the first element when there is only one of that atom.

Naming Rule: Vowel Dropping

When naming covalent compounds, a vowel (like 'a' or 'o') at the end of a prefix is dropped if the name of the second element begins with a vowel (e.g., 'pentoxide' instead of 'pentaoxide').

Expanded Octet

The ability of nonmetals in energy level three or lower (the third row of the periodic table or below) to accommodate more than eight electrons around them in a Lewis structure.

Covalent Bond

A chemical bond where two atoms share two electrons, represented by a line in a Lewis structure.

Dot Structure

A drawing that shows the valence electrons of an individual atom or in a molecule, using dots around the atom symbol.

Valence Electrons

The outermost electrons of an atom that participate in bonding, represented by dots in a dot structure.

Lone Pair

A pair of electrons on an atom that are already together and not involved in forming a bond; they are 'happy' in their pair.

Octet

The goal for most atoms to have eight valence electrons in their outermost shell to achieve stability, similar to noble gases.

Hydrogen's Electron Stability

Hydrogen aims to have two electrons to be stable, unlike other atoms that mostly seek an octet.

Double Bond

A covalent bond represented by two lines between atoms, indicating that four electrons (two pairs) are being shared.

Triple Bond

A covalent bond represented by three lines between atoms, indicating that six electrons (three pairs) are being shared.

Central Atom

In a Lewis structure, the atom that typically forms the most bonds, usually listed first in the chemical formula (hydrogen is rarely the central atom).

Naming Rule: No 'Mono' for First Element

In naming covalent compounds, the prefix 'mono' is not used for the first element when there is only one of that atom.

Naming Rule: Vowel Dropping

When naming covalent compounds, a vowel (like 'a' or 'o') at the end of a prefix is dropped if the name of the second element begins with a vowel (e.g., 'pentoxide' instead of 'pentaoxide').

Expanded Octet

The ability of nonmetals in energy level three or lower (the third row of the periodic table or below) to accommodate more than eight electrons around them in a Lewis structure.

What is the primary reason atoms form covalent bonds?

Atoms form covalent bonds to achieve a stable electron configuration, typically an octet (or a duet for hydrogen), by sharing electrons.

How can one determine the number of valence electrons for a main group element?

The number of valence electrons for a main group element is equal to its group number (for groups 1, 2, 13-18).

What is the significance of achieving an octet?

Achieving an octet (or a duet for hydrogen) makes atoms stable, mimicking the electron configuration of noble gases.

Besides being typically listed first, what other factor helps determine the central atom in a Lewis structure?

The central atom is often the least electronegative atom (excluding hydrogen, which is almost never central).

List common prefixes used in naming covalent compounds.

Mono-, di-, tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca-.