Final answer:
The order of elements from least conductive to most conductive is Si, Al, P.
Step-by-step explanation:
The elements aluminum (Al), silicon (Si), and phosphorus (P) can be ordered from the least conductive to the most conductive based on their locations in the periodic table. Aluminium is a metal and is a good conductor of electricity. Silicon is a metalloid, which means it has properties of both metals and nonmetals. It is a semiconductor, meaning it is not a great conductor of electricity but can still conduct under certain conditions. Phosphorus, on the other hand, is a nonmetal and is a poor conductor of electricity.
Therefore, based on their positions in the periodic table, the order from least conductive to most conductive would be Si, Al, P.
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