Identifying Non-linear Species
- Non-linear Species: A non-linear molecule is one that does not have a linear shape, meaning the bond angles are not 180 degrees.
- Linear Species: A linear molecule is one that has a straight shape, with bond angles of 180 degrees.

Given Species:
1. 15 (Unknown)
2. BeCl2(g) (Linear)
3. NH2 (Non-linear)
4. OH2 (Non-linear)
5. XeF2 (Linear)
6. N2O (Non-linear)
7. SO2 (Non-linear)
8. SF2 (Non-linear)

Total Non-linear Species: 5 out of 8 given species are non-linear.

Explanation:
- NH2: This molecule has a bent shape with a bond angle of approximately 104.5 degrees, making it non-linear.
- OH2: Water (H2O) has a bent shape with a bond angle of approximately 104.5 degrees, making it non-linear.
- N2O: Nitrous oxide has a bent shape with a bond angle of approximately 134 degrees, making it non-linear.
- SO2: Sulfur dioxide has a bent shape with a bond angle of approximately 119 degrees, making it non-linear.
- SF2: Sulfur difluoride has a bent shape with a bond angle of approximately 98 degrees, making it non-linear.
Therefore, out of the given species, NH2, OH2, N2O, SO2, and SF2 are non-linear molecules, totaling 5 non-linear species.