Chapter 8 - Covalent Bonding Flashcards
what is a formula unit
the lowest whole-number ratio of ions in an ionic compound
what is a molecule
neutral group of atoms joined together by covalent bonds
Why do atoms want to share electrons in a covalent bond?
to achieve an octet
How many single bonds can group 4a atoms make?
4
how many single bonds can 5a atoms make
3
how many single bonds can group 6a make
2
how many single bonds can group 7a make
1
which group forms diatomic molecules with a single bond
halogens
what other element forms a diatomic molecule with a single bond
hydrogen
which elements form diatomic molecules with a single bond
hydrogen
which elements form diatomic molecules with double bonds with example
Group 6a
oxygen
which elements form diatomic molecules with triple bonds with example
group 5a
nitrogen
what does a molecular formula tell you
how many atoms of each element a molecule contains
what does the structural formula tell you
arrangement of covalently bonded atoms
what does structural formula not tell you
shape
what is the bond dissociation energy
the energy required to break the bond between two covalently bonded atoms
which will have a smaller bond dissociation energy, single or double bond?
single
stronger bonds have what kind of bond dissociation energies
larger
what is resonance
the ability of a structure to be drawn as an electron dot structure two or more valid ways
are there exceptions to the octet rule?
yes
how are molecular orbitals formed
atomic orbitals overlap when sharing electrons
how many electrons can be in any molecular orbital
2
which model of the atom is the molecular orbital based on
quantum mechanical
what is VSEPR theory?
the repulsion between electron pairs causes molecular shapes to adjust so that the valence electron pairs stay as far apart as possible
angle measurement in tetrahedral
109.5
angle measurement in linear
180
angle measurement in trigonal pyramidal
107
angle measurement in trigonal planar
120
bent angle measurement
105, 116
