Kareem is standing 1105m away from the exploding cracker. Calculate the time needed for Kareem to hear the "BOOM" sound after the explosion.​

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?

Smallest intensity of a stimulus that you can detect 50 percent of the time is

Elements that have one valence electron and are very reactive are called