Option 1 states that light travels at different speeds in different media. This statement is correct. The speed of light varies depending on the medium it is passing through. For example, light travels slower in water compared to air or vacuum.

Option 2 states that light travels at almost 300 million meters per second in air. This statement is correct. The speed of light in a vacuum is approximately 300 million meters per second. While the speed of light might be slightly lower in air due to the presence of particles, it is still very close to the speed in a vacuum.

Option 3 states that light slows down as it leaves a water surface and enters the air. This statement is incorrect. When light passes from a denser medium like water to a less dense medium like air, it actually speeds up. This is because the refractive index of air is lower than water, causing the light to move faster.

Option 4 states that light speeds up as it leaves a glass surface and enters the air. This statement is correct. As with the previous explanation, light speeds up when it passes from a denser medium like glass to a less dense medium like air.

In conclusion, the statement in option 3 is the one that is not correct. Light speeds up as