pg 192-203

Question 1

what order are the atomic orbitals left to right

Answer 1

atom A, molecule, atom B

Question 2

what is the up axis on energy level diagram

Answer 2

energy

Question 3

what two principles are applied when adding the electrons

Answer 3

the aufbau exclusion principle

the pauli principle

Question 4

is the bonding or antibonding orbital lower in energy

Answer 4

bonding

Question 5

how to find the bond order according molecular orbital theory

Answer 5

number of filled bonding orbitals - number of filled antibonding orbitals

Question 6

how many does a half filled orbital contribute to the bond order

Answer 6

1/2

Question 7

what bond order makes a molecule paramagnetic

Answer 7

1/2

Question 8

what bond order makes a molecule diamagnetic

Answer 8

1

Question 9

why can He2 not happen

Answer 9

the four electrons contributed would fill one bonding and one antibonding orbital giving a bond order of 0

Question 10

what does overlap mean for molecular orbital theory

Answer 10

the degree of interaction between orbitals

Question 11

why is the bond dissociation enthalpy for Li2 lower than for H2

Answer 11

because of the lesser degree of overlap of wavefunctions from the 2s orbitals compared with the 1s orbitals

Question 12

what does in phase bonding of pz orbitals look like

Answer 12

like a quality street

Question 13

what does antibonding between pz orbitals look like

Answer 13

like two hourglasses next to each other with a nodal plane in between

Question 14

what does a pi orbital label mean

Answer 14

that it can rotate 180 degrees around the X-X orbital with a change of phase

Question 15

what does in phase combination of px orbitals look like

Answer 15

two ovals above and below the nuclei

Question 16

what does out of phase combination of px orbitals look like

Answer 16

like two ovals above and below the nuclei chopped in half

Question 17

why is pi overlap less effective than sigma overlap

Answer 17

because the orbitals are not pointed at each other meaning the molecular orbitals stabilize and destabilize less than sigma orbitals in energy level diagrams

Question 18

are the 1 pi bonding and antibonding orbitals higher or lower energy than the 3 sigma orbitals

Answer 18

they are in between the bonding and the antibonding orbital

Question 19

why is O2 paramagnetic

Answer 19

because it has unpaired electrons in the 1 pi antibonding orbitals

Question 20

where do the dotted lines from the 2p shells go

Answer 20

one from each bonding shell to the two atomic shells

Question 21

define isoelectronic

Answer 21

two different types of atoms with the same number of valence electrons