which describes amara's mistake?
she should have drawn a concave lens instead of a convex lens.
she should have drawn the image right-side up instead of upside down.
ray 2 should cross through the focal point on the right side of the lens.
ray 3 should point at a downward angle after passing through the len

Ray 2 should cross through the focal point on the right side of the lens.

Explanation:

For the image formation of the ray diagram we know that

1) Light ray passing through the lens which is passing through the focus before refraction must become parallel after refraction through lens

2) Light ray passing through the optical center of the lens must move out undeviated from the lens

3) light ray which is parallel to the principle axis before refraction must move through the focus after refraction through lens

so here we can see that ray 2 is incorrectly drawn here

so we have

Ray 2 should cross through the focal point on the right side of the lens.

chemical properties of thing

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.