1.The greenish blue of water is evidence for the

A) interaction between green and blue frequencies of light.
B) reflection of red light.
C) reflection of greenish-blue light.
D) absorption of greenish-blue light.
E) absorption of red light.

2.Atmospheric refraction tends to make daytimes
A) longer. B) shorter. C) no change in day length

1. It is usually E). Blue light is less absorbed than red in ocean and clear lake water, and it is blue light that is mainly reflected back.

However in glacial lakes, which are often a cloudy green, the main reason is C)

2. A) When the sun looks like it is just setting or rising, the REAL sun position is about a degree below the horizon, as a result of refraction.

Dawn and twilight extend the day also, but for a different reason. (upper atmosphere scattering)

1) The correct answer is A) interaction between green and blue frequencies of light. The greenish blue color of water occurs because water molecules absorb light at certain frequencies and reflect or transmit light at other frequencies. In the case of water, it absorbs light in the red part of the spectrum and reflects or transmits light in the green and blue parts of the spectrum. So the greenish blue color we perceive is due to the interaction between the green and blue frequencies of light.

2) The correct answer is B) shorter. Atmospheric refraction is the bending of light as it passes through Earth's atmosphere. This bending of light causes the apparent position of the Sun to be slightly higher in the sky than its actual position, especially when it is near the horizon. This results in an increase in the duration of daylight because the Sun appears to rise earlier and set later than it actually does. Therefore, atmospheric refraction tends to make daytimes shorter.

1. To determine the correct answer, we need to understand how the color of water is perceived. The color of an object is determined by the wavelengths of light it reflects or absorbs. In the case of water, it appears greenish blue. This means that certain frequencies of light are being absorbed or reflected by the water.

To find the answer, we can reason through the options:

A) Interaction between green and blue frequencies of light: This option seems plausible, as water appears greenish blue, implying the interaction of green and blue frequencies.

B) Reflection of red light: This option suggests that water reflects red light, but that doesn't explain the greenish blue color.

C) Reflection of greenish-blue light: This option implies that the water reflects the very color it appears to be, which seems logical.

D) Absorption of greenish-blue light: This option implies that the water absorbs the greenish-blue light, which contradicts its appearance.

E) Absorption of red light: This option suggests that water absorbs red light, but that doesn't explain the greenish blue color.

Based on the reasoning above, the most plausible answer is option C) reflection of greenish-blue light.

2. To determine the effect of atmospheric refraction on daytime, we need to understand what atmospheric refraction is. Atmospheric refraction is the bending of light as it passes through layers of Earth's atmosphere.

Now, let's consider the options:

A) Longer: If atmospheric refraction made daytime longer, it would imply that light is being bent towards us, resulting in longer daylight hours. However, this is not the case.

B) Shorter: If atmospheric refraction made daytime shorter, it would imply that light is being bent away from us, resulting in shorter daylight hours. This is the correct answer.

C) No change in day length: If atmospheric refraction caused no change in day length, it would imply that there is no bending of light occurring. However, this is not the case.

Based on the description of atmospheric refraction, the correct answer is B) shorter, as it is the most logical result of light bending away from us.