What is the function of nucleus?

Mary is conducting an experiment on how pollution affects plant growth. how can she ensure that her data are reliable?

Which theory was contradicted by experiments with the photoelectric effect? light spreads out after it passes through a small opening. as soon as light strikes metal, electrons will be ejected. visible light, regardless of color, will cause the ejection of electrons when striking metal. the kinetic energy of ejected electrons depends on the frequency of light that strikes the metal.

What is the most common form of matter in the universe