Data for permeation of a gas species through a solid are often presented in terms of a socalled permeation constant k, which is defined as the product of the solubility constant and the diffusivity: k = bdab. it is commonly expressed as the amount of gas [cm3/s at stp (273k and 1 atm)] permeating through a 1 cm2 cross section of solid of 1 cm thickness, for a partial pressure difference of 1 atm. for hydrogen through pyrex glass at 1000 k, k = 1.2 x 10^-8 cm^2/s∙atm and dab = 2 x 10^-8 cm^2/s. find the solubility of hydrogen in glass, in mass fraction units (i. e., grams of h2 per gram of glass per atmosphere partial pressure). take the density of the glass to be 2.4 g/cm3.

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of c is as shown here in the image.

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.