Answer:
The list of elements from increasing electronegativity: Calcium < magnesium < chlorine < argon < boron.
Explanation:
In the periodic table if you move from left to right there would be an increase in the electronegativity of the elements. If you move from the bottom to the top of the groups in the periodic table the electronegativity increases and if u move to the bottom from down its decreases.
Calcium is in the 2nd group below magnesium so calcium is the least electronegative among given elements then magnesium and then chlorine as it is top of magnesium then argon, as it is right to the chlorine, and boron has the most electronegativity as it is above rest of the elements.
Answer:
Near the boiling point of the solvent
Explanation:
The process of recrystallization is hinged on the fact that the amount of solute that can be dissolved by a solvent increases with temperature. The process involves creation of a solution by dissolving a solute in a solvent at or near its boiling point. At the boiling point of the solvent, the solute has a greater solubility in the solvent; not much volume of the hot solvent is required to dissolve the solute.
Before the solution is later cooled, you can now filter out insoluble impurities from the hot solvent. The quantity of the original solute drops appreciably because impurities have been removed. At this lower temperature, the solution becomes saturated and the solute can no longer be held in solution hence it forms pure crystals of solute, which can be recovered.
Recrystallization must be carried out using the proper solvent. The solute must be relatively insoluble in the solvent at room temperature but more soluble in the solvent at elevated temperature.
The uranium within these items is radioactive and should be treated with care. Uranium's most stable isotope, uranium-238, has a half-life of about 4,468,000,000 years. It decays into thorium-234 through alpha decay or decays through spontaneous fission.
