Grapevine trimming and other aromatics can be wrapped in aluminum foil with a few holes poked in it to?

Avariable that is not being directly tested during an experiment should be changed varied experimented controlled

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.

How many grams of mgbr2 are needed to produce 75g or metal?