Question

which of these techniques can be used to effectively separate an undissolved solid from a liquid?magnetismchromatographysettling, then decantationevaporation

Explanation:

• Magnetism only works if the solid is magnetic, so it's not a general effective method for undissolved solids.
• Chromatography is used to separate dissolved components, not undissolved solids.
• Settling lets undissolved solid sink to the bottom, then decantation pours off the liquid, separating the two effectively.
• Evaporation removes the liquid, leaving the solid, but it does not separate them (it eliminates the liquid instead of keeping both components separated).

Answer:

settling, then decantation