Carbon-12 is the most abundant isotope of carbon on Earth. Carbon-13 makes up about 1 percent of Earth's carbon atoms, and is useful for radioimaging. Which of the following is true?
a. Carbon-13 has more protons than carbon-12.
b. Carbon-13 has more neutrons than carbon-12.
c. Carbon-13 has more electrons than carbon-12.
d. Carbon-13 has an electronic configuration that is different from that of carbon-12.
e. Carbon-13 has an equal number of protons and neutrons.
Answer: B