Intra & Intermolecular Forces
There are two primary types of attractive forces between atoms:
1. Intermolecular Forces: These occur between neighboring molecules and tend to be
weaker.
2. Intramolecular Forces: These occur within a molecule, between the atoms, and are
generally stronger.
When water reaches its boiling point, which forces are disrupted? The intermolecular forces are
the ones that break because they’re not as strong as the bonds within a molecule.
Bonds
Before we dive into the different kinds of bonds, it's important to understand a few basic
principles:
Bond Formation: This is an exothermic reaction, meaning energy is released when a
bond is created.
Bond Breaking: This is an endothermic reaction, meaning energy is required to break a
bond—about 566J, to be precise.
The type of bond formed between atoms depends on their difference in electronegativity,
which is where knowing your periodic trends comes into play.
Chemical Bond
A chemical bond is essentially an attraction that holds atoms together, enabling the formation of
chemical substances. The valence electrons, or the outermost electrons of an atom, play a key
role in bonding. Atoms bond to achieve a stable arrangement, usually by filling their outer shell
with eight electrons (the octet rule). There are three primary types of chemical bonds, or
intramolecular forces: metallic, ionic, and covalent.
Metallic Bonding
Positive Ions (+): These are the fixed cations in the structure.
Electron Sea (-): A mobile sea of electrons surrounds these cations.
In metallic bonding, metal atoms release their electrons, creating positively charged ions. This
happens because metals typically have low electronegativity and ionization energy, allowing
their valence electrons to move freely.
, + = Fixed cation; - = sea of electrons
https://commons.wikimedia.org/wiki/File:Metallic_bonding.svg
Identifying Metallic Bonding:
Single Metal Element: This type of bonding is found in pure metals like zinc (Zn),
copper (Cu), gold (Au), etc.
Properties of Metals: The strong bonds in metals result in very high melting and boiling
points. The freely moving "sea" of electrons gives metals their characteristic malleability,
ductility, electrical conductivity, and generally low solubility in most substances.
Alloys: These are uniform mixtures (solutions) composed of two or more elements, with
at least one being a metal. Alloys, such as steel, brass, bronze, gold jewelry, and pewter,
are typically stronger than pure metals.
Metallic Bond Checklist
Valence electrons are mobile.
Electrons involved? Metals
Particles present? Cations and electrons
Type of attraction? Attraction between metallic particles
Melting and boiling point? High, except for Mercury
Water solubility? Low
There are two primary types of attractive forces between atoms:
1. Intermolecular Forces: These occur between neighboring molecules and tend to be
weaker.
2. Intramolecular Forces: These occur within a molecule, between the atoms, and are
generally stronger.
When water reaches its boiling point, which forces are disrupted? The intermolecular forces are
the ones that break because they’re not as strong as the bonds within a molecule.
Bonds
Before we dive into the different kinds of bonds, it's important to understand a few basic
principles:
Bond Formation: This is an exothermic reaction, meaning energy is released when a
bond is created.
Bond Breaking: This is an endothermic reaction, meaning energy is required to break a
bond—about 566J, to be precise.
The type of bond formed between atoms depends on their difference in electronegativity,
which is where knowing your periodic trends comes into play.
Chemical Bond
A chemical bond is essentially an attraction that holds atoms together, enabling the formation of
chemical substances. The valence electrons, or the outermost electrons of an atom, play a key
role in bonding. Atoms bond to achieve a stable arrangement, usually by filling their outer shell
with eight electrons (the octet rule). There are three primary types of chemical bonds, or
intramolecular forces: metallic, ionic, and covalent.
Metallic Bonding
Positive Ions (+): These are the fixed cations in the structure.
Electron Sea (-): A mobile sea of electrons surrounds these cations.
In metallic bonding, metal atoms release their electrons, creating positively charged ions. This
happens because metals typically have low electronegativity and ionization energy, allowing
their valence electrons to move freely.
, + = Fixed cation; - = sea of electrons
https://commons.wikimedia.org/wiki/File:Metallic_bonding.svg
Identifying Metallic Bonding:
Single Metal Element: This type of bonding is found in pure metals like zinc (Zn),
copper (Cu), gold (Au), etc.
Properties of Metals: The strong bonds in metals result in very high melting and boiling
points. The freely moving "sea" of electrons gives metals their characteristic malleability,
ductility, electrical conductivity, and generally low solubility in most substances.
Alloys: These are uniform mixtures (solutions) composed of two or more elements, with
at least one being a metal. Alloys, such as steel, brass, bronze, gold jewelry, and pewter,
are typically stronger than pure metals.
Metallic Bond Checklist
Valence electrons are mobile.
Electrons involved? Metals
Particles present? Cations and electrons
Type of attraction? Attraction between metallic particles
Melting and boiling point? High, except for Mercury
Water solubility? Low
