Which of the following sentences best compare conductors and insulators conductors and insulators allow electrons to flow freely conductors and insulators do not allow for electrons to flow freely insulators obstruct the flow of electrons whereas conductors allow electron to flow freely conductors obstruct the flow of electrons whereas insulators allow electron to flow freely

The correct answer is C. Insulators obstruct the flow of electrons whereas conductors allow electrons to flow freely.

Explanation:

Electricity refers to the flow or existence of an electrical charge that is connected to electrons. In this context, conductor materials refer to those materials that allow electricity to flow freely, this includes materials such as steel or copper. On the other hand, insulators are materials that stop or obstruct the flow of electrons and therefore the flow of electricity which includes materials such as wood or rubber. According to this, the statement that compares insulators and conductors is "Insulators obstruct the flow of electrons whereas conductors allow electrons to flow freely".

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.