When light waves first enter the eye, they first pass through this transparent layer where they are refracted

Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?

How many electrons does each element require in its valence shell to become stable?

Ahole in the ground in the shape of an inverted cone is 14 meters deep and has radius at the top of 11 meters. the cone is filled to the top with sawdust. the density of the sawdust depends upon the depth, x, following the formula ρ ( x ) = 2.5 + 1.2 e − 0.7 x kg/m3. find the total mass of sawdust in the conical hole.