Which of the following statements is/are example(s) of something that could be explained using chemistry? Select all that applying
The ripening of an apple ripens other apples.
Venus is the only planet that spins in the opposite direction to Earth.
A 200-pound person would only weigh 76 pounds on Mars,
A piece of cut potato turns brown when left out on the cutting board.

the first and fourth

Explanation:

Ripening and rotting can be explained as chemical changes in chemistry. The other two answers are physics-related. Venus rotates in an opposite direction because it has like forces with mercury, so it repels it, causing it to turn away. This is electromagnetic force, something definitely not directly related to chemistry. The 200-pound person problem has to do with weight, mass, and gravitational force, which is mainly in physics.

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.