covalent bonding and structure Flashcards
1
Q
what is a covalent bond
A
an electrostatic attraction between shared pairs of electrons and the positively charged nuclei
2
Q
how are covalent bonds formed
A
a covalent bond occurs because two orbitals, each contain one electron, overlap
this is shown for H2. the strength of the bond is proportional to the amount of overlap of the orbitals
3
Q
exceptions to the octet rule
A
- boron is stable with fewer than eight electron in their outer shell
- atoms in period three and higher, such as sulfur, phosphorus and chlorine can form expanded octets with up to twelve electrons in their valence shell
4
Q
what is a dative bond
A
both electrons in a shared pair originate from the same atom
5
Q
what structure giant or simple do all covalent structures have
A
simple
6
Q
what are the 4 exceptions of the simple structure
A
- silicon
- silicon dioxide (silica), SiO2
- allotropes of carbon = diamond and graphite
7
Q
strength of intermolecular bonds
A
weak
8
Q
strength of intramolecular bonds - covalent bonds
A
strong
