Which part of the eye controls whether or not the pupil dilates or constricts?

iris

cornea

retina

optic nerve

Which statement describes an Arrhenius acid? It is a proton donor. It is a proton acceptor. It produces hydroxide ions in a solution. It produces hydrogen ions in a solution.

For each structure shown below, determine the number of π electrons. indicate whether the structure is aromatic, nonaromatic, or antiaromatic.

Are phase changes physical or chemical changes? why?

The mass of Earth is 5.974x10^24 kg. Assume that Earth is a sphere of diameter 1.28x10^4 km and calculate the average density of Earth in grams per cubic centimeter.

Put the four stages of public policy development in the correct order

To what chemical reaction class does this reaction belong? 2 mg (s) + o2 (g) 2 mgo (s)

Which best illustrates how particle arrangement changes when solids change into liquids

Express in scientific notation (6.0x10^4) (3.1x10^-1)

How do you measure the mass of a liquid?

Given the following information, calculate the mass for B-11. B-10 has a natural abundance of 19.9 percent, while B-11 has a natural abundance of 80.1 percent. The mass of B-10 is 10.013 amu.