A closed system is:

completely closed to the outside environment.

only slightly exposed to the outside environment.

in constant exchange with the environment

completely exposed to the outside environment.

2. If compound A is more polar than compound B, which compound will have the highest Rf value on a TLC plate that is eluted with ethyl acetate? Which compound will have the highest Rf value if the plate is eluted with dichloromethane

What is oxidized and what is reduced in this reaction? N2H4 (l) + 2H2O2 (l) → N2 (g) + 4H2O (g) A) N is reduced and H is oxidized. B) N is reduced and O is oxidized. C) N is oxidized and O is reduced. D) N is oxidized and H is reduced.

If 200. mL of water is added to 300. mL of an aqueous solution that is 0.725 M in potassium sulfate, what is the concentration of potassium ions in the final solution?

Gasoline in a storage tank potential or kinetic?

If you are given only the amount, in moles, of an unidentified chemical quantity, you can calculate the number of: representative particles in the sample << I choose this one am i right?

Each of the following reactions shows a solute dissolved in water. Classify each solute as a strong electrolyte, a weak electrolyte, or a nonelectrolyte.

Name two events involving electrons that can result in the formation of chemical bonds between atoms.

Which element among elements 2, 4, and 6 has the lowest ionization energy?

What is the pressure, in mm Hg, of 2.50 moles of an ideal gas if it has a volume of 50.0 liters when the temperature is 27.0° C?

What element has the same valence electrons as carbon A) N B) AI C) Si or D) Be