Which of these is always equal to the molar mass of any element?

its atomic number
its atomic weight
its atomic formula
its atomic structure

Option (b) is the correct answer.

Explanation:

Atomic weight is also known as atomic mass or molar mass of an atom.

Atomic mass means the sum of total number of protons and neutrons present in an atom.

For example, atomic mass of HCl is atomic mass of hydrogen + atomic mass of chlorine.

That is, atomic mass of HCl is 1.01 g/mol + 35.453 g/mol = 36.463 g/mol

Thus, we can conclude that molar mass of any element is always equal to its atomic weight.

why is cellular respiration important for homeostasis?

it changes food into energy that the organism can use.

which of the following is most likely to happen if a cell is not able to divide?

the cell will not be replaced when it is damaged.

explanation:

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.