Lewis Structures

Question 1

lewis structure

Answer 1

simple notation of dots and crosses to represent outer energy level electrons of all atoms within molecule

Question 2

What are the steps to making a lewis structure?

Answer 2

calculate total number of valence electrons
draw skeletal structure of molecule to show how atoms are linked together
use lin to show electron pair and put a pair in each bond between atoms
if not enough electrons to complete octets form double/triple bonds
check that total number of electrons in structure equals calculation

Question 3

What do you include when drawing lewis structures of ions?

Answer 3

put structure in brackets with charge shown outside (include ionic charge in actual structure as well)

Question 4

What are the two exceptions to the octet rule?

Answer 4

incomplete octet

expanded octet

Question 5

incomplete octet

Answer 5

small atoms (e.g. Be and B) can form stable molecules with fewer than eight electrons in valence shell

Question 6

What ideas are associated with incomplete octets?

Answer 6

said to be electron deficient so have tendence to accept an electron pair from molecule with a lone pair

Question 7

expanded octet

Answer 7

molecules with larger central atoms (beyond period 3) can hold 18 electrons in valence shell
d orbitals available in valence shell have energy values relatively close to p orbitals