You probably already know the names of some molecules. identify which compound (water, salt, carbon dioxide, or methane) corresponds to each of the following chemical formulas. h2o is . co2 is . nacl is . ch4 is .

Explanation:

Water has a formula which represents two hydrogen atoms are attached to one oxygen atom. Therefore, the formula of water is .

Salt is also known as sodium chloride. Its formula represents that one sodium atom is attached to one chlorine atom, therefore, its formula is NaCl.

Carbon dioxide has a formula which represents one carbon atom is attached to two oxygen atoms. Therefore, its formula is .

Methane has a formula which represents one carbon atom is attached to four hydrogen atoms. Therefore, its formula is .

Thus, we can conclude that is water, is carbon dioxide, NaCl is salt, and is methane.

a boiling water reactor does not boil the water. a pressurized water reactor boils the water faster. a pressurized water reactor is heated directly by the core. a pressurized water reactor does not use fission.

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.