Chapter 3 - Covalent bonds Flashcards
What is a covalent bond?
A covalent bond forms when two non-metal atoms share electrons to achieve a full outer shell
What do electron dot (Lewis) diagrams represent?
They show only valence electrons as dots or crosses around the atoms
What is a single bond?
One shared pair of electrons
What is a double bond?
Two shared pairs of electrons
What is a triple bond?
Three shared pairs of electrons
What is a valence structure?
A simplified representation of Lewis diagrams using lines for bonds
What does VSEPR stand for?
Valence Shell Electron Pair Repulsion
What determines the shape of a molecule according to VSEPR theory?
Electrons repel each other, causing molecules to arrange themselves as far apart as possible
What are electron groups in molecular shapes?
Bonding electrons and non-bonding electrons (lone pairs)
What is a linear molecular shape?
Molecule shape where there are 2 bonding pairs and 0 lone pairs
What is a V-shaped molecular shape?
Molecule shape with 2 bonding pairs and 2 lone pairs
What is a pyramidal molecular shape?
Molecule shape with 3 bonding pairs and 1 lone pair
What is a tetrahedral molecular shape?
Molecule shape with 4 bonding pairs and 0 lone pairs
What is a structural formula?
A simpler way to represent molecules using lines for bonds
What is electronegativity?
How strongly an atom pulls electrons towards itself
What characterizes a non-polar bond?
Electrons are shared equally
What characterizes a polar bond?
Electrons are shared unequally, causing a slight charge
What is a non-polar molecule?
A symmetrical molecule where dipoles cancel out
What is a polar molecule?
An asymmetrical molecule where dipoles do not cancel
What is a dipole?
A molecule with a slightly positive and slightly negative side
What is the difference between intramolecular and intermolecular bonds?
Intramolecular bonds are strong bonds inside molecules, while intermolecular forces are weaker forces between molecules
What are intermolecular forces (IMFs)?
Forces that hold molecules together, affecting melting points, boiling points, and density
What are dispersion forces?
The weakest intermolecular force found in all molecules due to temporary dipoles
What are dipole-dipole forces?
Medium strength forces occurring only in polar molecules with permanent dipoles
What is hydrogen bonding?
The strongest type of intermolecular force occurring when H is bonded to N, O, or F
Arrange the types of intermolecular forces from strongest to weakest
- Hydrogen bonding
- Dipole-dipole forces
- Dispersion forces
Fill in the blank: A polar bear is a _______ molecule.
polar
Fill in the blank: A normal bear is a _______ molecule.
non-polar
What is the key idea of covalent bonds?
Non-metals share electrons to form strong bonds
What do Lewis diagrams show?
Valence electrons as dots or crosses
What determines molecular shape according to VSEPR?
Electron repulsion
What does polarity depend on?
Symmetry and electronegativity
What causes dipoles?
Charge separation due to unequal electron sharing
