Which of the following is true about electron energy shells?
a) They represent regions around the nucleus in which the electrons orbit.
b) The shells closest to the nucleus contain electrons with higher energy.
c) They contain electrons of the same energy.
d) a and b only.
e) a and c only.
How are Carbon-13 and Nitrogen-15 respectively different from the more abundant isotopes Carbon-12 and Nitrogen-14? Carbon-13 and Nitrogen-15 _______________:
a) Each have an extra neutron.
b) Each have an extra proton.
c) Each have one less neutron.
d) Each have one less proton.
e) Each have one less electron.
Radioactive isotopes are utilized for all of the following except:
a) Dating fossilized material of once living things.
b) Radiation treatment to slow or stop the development of cancer cells.
c) Labeling regions of the body with radioactivity for special imaging techniques.
d) All of the above.