## Bond Angles

(Polar molecules, Non-polar molecules, etc.)

Shirley Liu 2I
Posts: 64
Joined: Fri Sep 28, 2018 12:16 am

### Bond Angles

Atoms in molecules have molecular shapes that try to get each atom as far away from each other. However, why are tetrahedral angles 109.5 degrees each instead of 90 degrees if we follow the rationale of 360degrees/4?

juliefilice 4A
Posts: 31
Joined: Fri Sep 28, 2018 12:27 am

### Re: Bond Angles

We represent molecules using 2D Lewis structures, but they really exist in 3D space. This means that the atoms can get father away from each other, going behind or coming in front of the central atom, which explains the larger bond angle of 109.5

Tiffany_Cacy_3D
Posts: 70
Joined: Fri Sep 28, 2018 12:24 am

### Re: Bond Angles

In that instance you would have to consider a 3D model instead of a 2D model. The surrounding atoms want to be as far away from each other as possible so a three dimensional model provides the most space between the atoms.

Posts: 74
Joined: Fri Sep 28, 2018 12:29 am

### Re: Bond Angles

Tetrahedrals are 3D shapes, not 2D. If they were 2D shapes then the angles would be 90 degrees. Remember that the shapes of molecules should be in 3D since we live in a 3D world

Zenita Leang 2K
Posts: 67
Joined: Fri Sep 28, 2018 12:28 am

### Re: Bond Angles

Tetrahedral shaped atoms have bonds at a 109.5 degree angle because of its 3 dimensional shape! If each bond was 90 degrees away from each other, it would be more similar to having a flat shape but to maximize the space that the atom has (and because of the negatively charged electron's repulsion from each other), the bonds are at a 109.5 degree angle.