Choose the appropriate technique below for separating these mixtures into their constituents. (Diffusion, Solvent Extraction, Chromatography, Sublimation, Fractional Distillation and Distillation.
I. Solid iodine and solid calcium carbonate
II. Pigments extracted from the bark of a tree
III. Solid sodium chloride and solid sulphur
IV. Water and propanol
V. Liquid
VI. Solid sodium carbonate and solid calcium
VII. Gaseous hydrogen and gaseous sulphur (iv) oxide.

What is the empirical formula of vanadium 1 oxide given that 20.38 grams of vandium combines with oxygen to form 23.58 grams of the oxide

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.

This question is about electrolysis. metal spoons can be coated with silver. this is called electroplating. suggest one reason why spoons are electroplated?