unit 1a: shapes of molecules

Question 1

shared electrons in a covalent charge

Answer 1

negatively charged so they repel the electrons in other bonds in a molecule

Question 2

particular shapes in molecules because

Answer 2

they try to minimise repulsive forces

Question 3

VSEPR

Answer 3

valence shell electron pair repulsion

Question 4

five basic shapes depending on the number of electron pairs

Answer 4

linear, trigonal planar, tetrahedral, trigonal bipyramidal, octahedral

Question 5

dative bond

Answer 5

when both electrons come from the same atom

Question 6

bonding pairs

Answer 6

electrons pairs involved in bonding

Question 7

non-bonding pairs

Answer 7

these have a greater repulsive effect than bonding pairs so their presence in a molecule causes slightly distorted shapes

Question 8

determining if there are non-bonding pairs

Answer 8

subtract the number of atoms around the central atom from the number of electron pairs, any left over must be non-bonding

Question 9

linear bond angles

Answer 9

180°

Question 10

trigonal planar bond angles

Answer 10

120°

Question 11

tetrahedral bond angles

Answer 11

109.5°

Question 12

trigonal bipyramidal bond angles

Answer 12

120° and 90°

Question 13

octahedral bond angles

Answer 13

90°

Question 14

3 bonding 1 non-bonding

Answer 14

trigonal pyramidal, 107°

Question 15

2 bonding 2 non-bonding

Answer 15

angular, 105°

Question 16

3 bonding 2 non-bonding

Answer 16

T-shape, <90° <120°

Question 17

4 bonding 2 non-bonding

Answer 17

square planar

Question 18

4 bonding 1 non-bonding

Answer 18

seesaw

Question 19

2 bonding 3 non-bonding

Answer 19

linear

Question 20

5 bonding 1 non-bonding

Answer 20

square pyramidal