Calculate the concentration of solution (in%) obtained by adding of 200 g of water to 400 g of 30% solution: A) 20
B) 23
C) 25
D) 10
E) 15
( i found A but i doubt it)

What happens when an acid dissolves?

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.

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.