The answer is true
Refraction is an effect that occurs when a light wave, incident at an angle away from the normal, passes a boundary from one medium into another in which there is a change in velocity of the light.The wavelength decreases as the light enters the medium and the light wave changes direction.
- By changing three atom bond angle , we can change molecular polarity. if bond angle is 120° and all atom has same electronegativity, the resultant polarity ( dipole moment ) become zero. we can change bond anngle either less than or greater than 120°, but not exactly 120
- Replacing one or more atom with different atoms having electro negativity values also make molecular poles.
- By placing molecules under external electric field or magnetic field also causes to the molecule.
Answer:
B. is often done in nature preserves
Explanation:
edge 2021