Bill is experimenting with two simple machines. How will he know which machine is more efficient?
O It will use less force to do the same amount of work.
O It will use more force to do the same amount of work.
O It will be lighter and stronger than the other simple machine.
It will not be possible to tell which simple machine is more efficient.

Click the button that shows the correct relationship of the electron affinities of the elements sodium and phosphorus. sodium’s electron affinity value is more negative than the electron affinity value of phosphorus. phosphorus’ electron affinity value is more negative than the electron affinity value of sodium. this information cannot be determined using the periodic table. answer is b on e2020.