The mass of an atom of 12C is exactly 12 atomic mass units. Which of the following describes a mole of 12C atoms?
a) a sample which weighs exactly 12 atomic mass units
b) a sample which contains 6.02 × 1023 atoms of 12C
c) both a and b
d) neither a nor b
The correct answer is b) a sample which contains 6.02 × 10^23 atoms of 12C.
A mole is a unit of measurement in chemistry that represents a specific number of particles, which is 6.02 × 10^23. In other words, one mole of any substance contains Avogadro's number of particles.
In this case, a mole of 12C atoms would contain 6.02 × 10^23 atoms of 12C. The mass of a mole of 12C atoms is not mentioned in the given information, so option a) is incorrect. Therefore, the correct answer is b) a sample which contains 6.02 × 10^23 atoms of 12C.