If the symbol X represents a central atom, Y represents outer atoms, and Z represents lone pairs on the central atom, the structure Y-:X:-Y could be abbreviated as XY2Z2.

Classify these structures according to their shape.
XY2Z,XY2Z2,XY2Z3,XY3Z,XY3Z2,XY4Z,XY4Z2,XY5Z

The categories are linear, bent(~120), bent(~109), trigonal pyramidal, t-shaped, see-saw, square planar, square pyramidal

I would classify it as angular (like H2O molecules with angle about 105 or so but the table you wrote below shows XY2Z2 as bent (about 120)

Here is the classification of the given structures according to their shape:

1. XY2Z: This structure has a linear shape.
2. XY2Z2: This structure has a bent shape (~120 degrees).
3. XY2Z3: This structure has a trigonal pyramidal shape.
4. XY3Z: This structure has a trigonal pyramidal shape.
5. XY3Z2: This structure has a T-shaped shape.
6. XY4Z: This structure has a see-saw shape.
7. XY4Z2: This structure has a square planar shape.
8. XY5Z: This structure has a square pyramidal shape.

To classify the structures according to their shape, you need to determine the number of outer atoms (Y), lone pairs (Z), and the central atom (X) in each structure.

1. XY2Z - This structure has 2 outer atoms and 1 lone pair on the central atom. It is classified as bent (~120 degrees).

2. XY2Z2 - This structure has 2 outer atoms and 2 lone pairs on the central atom. It is also classified as bent (~109 degrees), but the bond angle is slightly smaller than in XY2Z.

3. XY2Z3 - This structure has 2 outer atoms and 3 lone pairs on the central atom. It is classified as linear because the lone pairs repel each other and the outer atoms, causing a linear arrangement.

4. XY3Z - This structure has 3 outer atoms and 1 lone pair on the central atom. It is classified as trigonal pyramidal because the lone pair gives a pyramidal shape to the molecule.

5. XY3Z2 - This structure has 3 outer atoms and 2 lone pairs on the central atom. It is classified as T-shaped because of the orientation of the lone pairs and outer atoms.

6. XY4Z - This structure has 4 outer atoms and 1 lone pair on the central atom. It is classified as see-saw because of the distorted shape, with one outer atom and the lone pair slightly offset from the others.

7. XY4Z2 - This structure has 4 outer atoms and 2 lone pairs on the central atom. It is classified as square planar because the molecules adopt a flat, square shape due to the presence of two lone pairs.

8. XY5Z - This structure has 5 outer atoms and 1 lone pair on the central atom. It is classified as square pyramidal because the lone pair gives a pyramidal shape to the molecule with a square base.

By classifying these structures according to their shape, you can understand their geometries and predict their properties and reactivity.