PLEASE HELP ME PLEASEEE AND QUICK. NO TROLL ACCOUNT AND POSTING A LINK TO NO WHERE, PLEASE. DONT. UR WASTING MY TIME.
SOMEONE PLEASE BE NICE.

Please answer ALL THREE if u can, thank you so so so so much

In a simplified model of the human eye, the aqueous and vitreous humors and the lens all have a refractive index of 1.40, and all the refraction occurs at the cornea, whose vertex is 2.60 cm from the retina. what should be the radius of curvature of the cornea such that the image of an object 40.0 cm from the cornea’s vertex is focused on the retina?

Earth's atmosphere is composed of mostly two gases. name the two gases that make up the majority of the atmosphere and use the pie chart to tell the percentages of each.

Which of the following is a measure of the amount of light a star directly emits?               a.  luminosity    b.  intensity    c.  wavelength    d.  brightness