Which property typically indicates strong intermolecular forces are present in a liquid? A) low heat of vaporization B) low critical temperature C) low vapor pressure D) low boiling point E) low melting point

C) low vapor pressure

Explanation:

Vapor pressure refers to the pressure created by the vapor produced at a given temperature in a closed container. The pressure created as a result of the production of vapor above the liquid in a closed container. Vapor pressure works as the result of the force of the intermolecular force. When a liquid does evaporates easily it exemplifies that it has low vapor pressure. When the liquid evaporates easily and quickly, it exemplifies that it has high vapor pressure.

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.

the dependant variable is spilled water

the independent is the heat