Basic shapes of molecules

Question 1

Lone pairs cause more repulsion than bonding pairs because?

Answer 1

they are closer to the nucleus.

Question 2

To predict the shape of a molecule or ion, first determine the total number of electron pairs (bonding + lone) on the central atom using these steps:

Answer 2

1.Identify the central atom bonded to all other atoms.
2.Find the number of outer shell electrons of the central atom using its group number.
3.Add one electron for each bonded atom.
4.If the species is an ion, add one electron for each negative charge or subtract one electron for each positive charge.
5.Divide the total number of electrons by two to get the number of electron pairs.
6.Subtract the number of bonds from the number of electron pairs to determine the number of lone pairs.

Question 3

if the molecule has 2 pairs of electrons what is the name of the shape and bond angle?

Answer 3

-linear
-180

Question 4

if the molecule has 3 pairs of electrons what is the name of the shape and bond angle?

Answer 4

-trigonal planar
-120

Question 5

if the molecule has 4 pairs of electrons what is the name of the shape and bond angle?

Answer 5

-tetrahedral
-109.5

Question 6

if the molecule has 5 pairs of electrons what is the name of the shape and bond angle?

Answer 6

-trigonal pyramidal
-120,90

Question 7

if the molecule has 6 pairs of electrons what is the name of the shape and bond angle?

Answer 7

-octahedral
-90