Carbon-14 has the same .
a. atomic number and thus number of neutrons as carbon-13 b. number of protons but more neutrons than carbon-12
c. atomic number and atomic mass as carbon-12
d. atomic mass as both carbon-12 and carbon-13

b. number of protons but more neutrons than carbon-12

Explanation:

Isotopes are elements which have same atomic number but different mass number.

Atomic number is defined as the number of protons or number of electrons that are present in an electrically neutral atom.

Atomic number = Number of electrons = Number of protons

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons

a) C-14 , Number of protons = 6

6 + Number of neutrons = 14, Number of neutrons = 8

b) C-13, Number of protons = 6

6 + Number of neutrons = 13, Number of neutrons = 7

c) C-12, Number of protons = 6

6 + Number of neutrons = 12, Number of neutrons = 6

Thus Carbon-14 has the same number of protons but more neutrons than carbon-12

the answer to your question is c.

if you read the house of usher you should know that the house was haunted

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.